Beware the Silly Ones: She may come off as nasal, big-haired, and desperate, but, people tend to forget she is also a hypermanipulative master of the Cool and Unusual Punishment, most often in the form of forced proximity with her overbearing mother. She's also skilled with Jewish guilt, and can reduce feelings of triumph to bitter sadness with a snap of her fingers.
Big Eater: Though not to the same degree as her mother.
Big Sister Mentor: To the Sheffield children, especially Maggie. This was established in the season 1 episode "The Nuchshlep", when Fran tells Maggie she's too old for a nanny. Though this raises many problems once Fran and Maxwell are married, as Fran is expected to side with Maxwell on issues about the children.
Book Dumb: Not very educated but extremely street smart.
Pop Cultured Badass: Fran is very much this trope. She has an extremely detailed knowledge of pop culture, has the TV Guide memorized, and in at least one case even used her knowledge of pop culture to successfully track down the guy who kidnapped CC's dog (It Makes Sense in Context). Arguably, Fran's ability to personify this trope was one of the reasons she was able to reinvigorate the dry Sheffield household when she moved in.
Always Someone Better: He deals with this twice over. In the present day, he's always playing second fiddle to Andrew Lloyd Webber; during his school days, he always seemed to be coming in second place to Jeremy Irons.
Ambiguously Gay: This was occasionally joked at, mostly since he had a woman as gorgeous as Fran, who was blatantly head over heels for him, trotting around under his nose in short skirts and high heels for years and never made a move. In one episode, when he found himself still attracted to Fran while she was disguised as a man named "Wilbur" he made the joke a lot of others had made, wondering in spending years producing musical theater had finally affected him.
Fake Brit: Daniel Davis is actually from Arkansas, but his accent is so good that when the show premiered in the UK, viewers thought that he should help Charles Shaughnessy (an actual Londoner) with his accent.
Not just a Londoner, an honest-to-God Lord (he is the 5th Baron Shaughnessy).
I Was Quite a Looker: In one episode, when Max wrote a thinly veiled story based on his life, Niles is moping that he wasn't invited to the premiere since he was the inspiration for the character of the houseboy. Fran snarks, "He was twenty-five with a blond pompadour and an impish grin." Niles bites back, "Well, so was I six hundred thousand Brillo pads ago."
"The Reason You Suck" Speech: He delivers one to C.C. after she begins mocking him for thinking he had a chance with her. Niles lays into her that at least he is trying to move on from his rejection, whereas she's spent a good chunk of her life chasing after a man (Maxwell) who has no interest in her and never will, and is still chasing after him even though he's now married and is having a child with his new wife. The thing is, rather than give a snappy comeback, this really hits C.C. where it hurts and she decides to resign from being Maxwell's partner. She doesn't, and C.C. and Niles really do get together.
Antagonist in Mourning: Happens twice to C.C.. Once when Fran leaves to become a soap opera star, C.C. is ecstatic until she finds out that Maxwell has hired Heather Biblow to take over as nanny. When Fran returns, C.C. hugs her, exclaiming "Don't you ever leave me again!" to a perplexed Fran. The second time was after Niles suffers a heart attack during a verbal spar with him.
Child Hater: She can't even remember the names of Maxwell's children, or even the number, despite knowing them all their lives, and working from their home. Also, one time, when she was entertaining a group of ladies she mentioned how they were deciding between donating to their show or a Children's Milk Fund, saying how she didn't want any thirsty little brats getting in her way.
In another episode, she was able to tell, over the car phone, that Fran had hit a rabbit while driving by recognizing the noise. To repeat: She was able, over the phone, to identify what Fran hit, down to the species, merely by the sound it made when it was hit by a car.
Hide Your Pregnancy: Lauren Lane became pregnant during season 5, so it was written that C.C. got institutionalized after learning that Fran and Maxwell got engaged. In one episode, she lampshades Seinfeld's use of this trope on Elaine Benes, later entering the room with a large sign that said "BABY" over her body.
Also a justified trope. It'd be out-of-character for her to be pregnant, since she's portrayed as hopeless at getting dates throughout most of the show.
Informed Deformity: A quite jarring case: throughout the series Niles insinuates that C.C. is unattractive, despite the fact that she actually looks quite beautiful (it was her personality that was unattractive!). Justified later on in the series when it turns out that Niles has just been saying this to cover up the fact that he's actually madly in love with C.C. (For the most part, in the early episodes, it would appear that Niles simply hates her so much he's coming up with every insult he can to throw at her. He also calls her a cow, a hooker, and a witch.)
It's All About Me: Even though she mellows out in the end, she still goes on and on about herself, even going as far as having a priest marry her and Niles while Fran's in labor.
Although, that was Fran's idea. She bad been violently ill ever since Niles proposed, and Fran said that as soon as she said "I Do", her jitters would go away.
It turns out though, that she was feeling ill because she's pregnant with Niles' child. Although C.C. did say she was feeling better afterwards.
C.C.: Nanny Fine, you're right! I don't feel like I'm gonna throw up anymore!
Fran: Question: When they shot Bambi's mother, did you find that a sad moment?... At all?
C.C.: I'm sure she's mounted on a nice wall in a fine home somewhere.
Large Ham: Especially in the first seasons, her two expressions were either icy indifference or full-throated rage.
Laser-Guided Karma: Often, usually delivered swiftly by the machinations of Fran and/or Niles. In fact, most of Niles' barbs and pranks are done in direct response to a moment of Jerk Ass or callousness on C.C.'s part.
Meaningful Name: Her full name Chastity-Claire, considering how unlucky she is with men, especially Maxwell.
Probably also an Ironic Name, since it's such a sweet, feminine name and C.C.'s so... not. It should be noted that when this is announced, the entire room (including Fran who's in labor) stop and look at her rather surprised.
Intergenerational Friendship: It was a plot point at a few times that, even though Fran was at least a generation older than her and hired to be a caregiver, Maggie was frankly too old to have a nanny anymore (she started the show in her early-to-mid teens,) and they acted more like sisters or girlfriends than anything else (it became a problem later when Fran really did become her mother.)
Took a Level in Badass: As part of her Character Development. In early episodes, her only response to Brighton's barbs was to scream out "Shut up, Brighton!" and storm out of the room angry and/or hurt. By the end, thanks to Fran working on her self-esteem and teaching her how to stand up to him, by the end, she was able to give as good as she got and would get the better of him frequently.
Creepy Child: Especially in earlier seasons, her therapy and subsequent extensive knowledge of psychology made her come across as a little twisted. In the pilot, after Fran snarked about Grace saying her therapist took her back through her childhood (She was about 7 at the time,) Grace turned to her and said, "Oh, you have no idea how complicated I am."
Mood Whiplash: Part of Grace's charm was the fact that she would pinball back and forth between a Wise Beyond Their Years pseudo-adult and a very typical little girl, once saying her ideal man was a combination of Barney... and Ted Koppel.
Out of Focus: Seasons 3-6, probably to make room for Fran's growing romance with Maxwell, and more story lines involving Val, Sylvia, and Yetta (and possibly due to the fact that Madeline Zima was the only one still under age and subject to child labor laws.)
Characterization Marches On: In an early episode, she actually took in the entire main cast during a blizzard and kept all of them well-fed. Later on, she was quick to snatch up any food someone else was about to sink their teeth into.
Potentially justified since it was a major crisis (worst blizzard in 30 years) and the family was stranded in her house. The rest of the time, since the Sheffield household was much better off than she was, all food was fair game (she did seem willing to offer food any time they were in her home.)
Informed Deformity: While Sylvia was a Big Eater and definitely a bigger woman, in show, they portrayed her as a whale. During one of her many elaborate freakouts, she threatened to throw herself in the Hudson River, to which Fran responded "Ma, flooding New Jersey is not gonna solve anything!"
To be fair though, playing a stereotypical Jewish Mother whose daughter is over 30, Sylvia would ship Fran with just about anyone. Fran even commented once that her mother would have been thrilled with her hooking up with a successful, professional woman if not for the fact said lesbian wasn't Jewish.
Well-Intentioned Extremist: A typical trait of the My Beloved Smother on sitcoms of the time, she always genuinely seemed concerned with Fran's happiness (she just had trouble understanding that happy =/= married.) She would pair up Fran with any available male she saw. Also, when it was revealed that Fran was a Former Teen Rebel, it was mentioned how Fran had no privacy as a child. Sylvia's acrylic nails could open any door she needed through ("Doors, diaries, my ex-boyfriend Chevy," according to Fran,) and casually mentioned reading her diary like it was a cookbook.