- It happens during the discussion about the game's ending:"So. Which ending did you get?"
"The one where you take of your mask and die in your parents' arms."
Claire abandoned her normally graceful, bubbly giggle to go 'pffffft' instead. "You have to be ridiculously goody-goody to get that ending!"
- Alternatively In Please Don't Tell My Parents You Believe Her, Heart of Gold Penny will be the one who ends up sacrificing herself - possibly as some part of helping Real Penny getting her body back from her evil super power with Heart of Gold ending up back in the Robot Penny body - and will die in Penny's arms. Afterall Penny created the Heart of Gold so in a way she is her parent. Also noted that the Heart of Gold is the 'good' (or at least, more good) version of Penny.
- It's stated on numerous occasions, that Abigail looks very similar to how Penny will look in a few years.
- After witnessing Penny's inventing power in the superkids clubhouse, Barbara is neither surprised nor afraid of how Penny was acting during that time. She also immediately recognizes that Penny doesn't remember anything from the time spent inventing.
- The Audit's least favorite statistic correlates combinations of hair style and color and powers with a "possession" mechanic. This could be because Penny actually fits the profile and it was pointed out to Mrs. Akk sometime prior to the story.
- It seems like most defeated superheroes are left laying unconscious on the ground or otherwise immobilized/restrained by supervillains who don't take off their foes masks/costumes so that things "don't get personal". Likewise, either Spider is incredibly good and has a support network for creating new false identities for captured supervillains, or supervillains are allowed to stay in costume/not get finger printed/have their secret identity remain a secret even after being captured. As absurd as this might sound, it does avoid creating more situations like Deadly Flame, who felt like there was no place left for him in society so he might as well do as much damage to it on his way out as possible. Either that, or there are some rules where it is illegal to try and arrest/detain supervillains unless they're actively committing a crime so that supervillain who lacks a secret identity is still allowed to live a fairly normal life. This process helps avoid making supervillains feel like they can't go legit or change sides should they desire to and aren't forced into a life of crime from which their is no escape. The only reason that Penny and her friends had to worry about having their own identities get revealed if they were captured in the first book was because nobody took them seriously enough to grant them the sort of blanket Secret Identity protection that "professionals" get.
- The superhero and supervillain community in LA has been carefully guided by Spider (and possibly her counterpart on the other side of the line if there is a Big Good in the superhero community) to be more like wrestling; lots of big flashy speeches and posing and a minimum of people actually getting hurt. What if a new group of younger superheroes show up however who combine the worst traits of Marcia and Claudia from book one? Superheroes who really want to hunt down supervillains and take them to jail even if they're out of costume and don't have a problem with getting personal. Now if they were adults they could doubtlessly be dealt with by the villain equivalent of Morning Dove, but given their age a softer touch is clearly required. Thus she'll turn to her new favorite trouble shooters, the Inscrutable Machine to either convince these heroes to see things the LA way, or humiliate them enough that they give up.
In the third book her first fight with Lighting Wisp and Sharky is directly described as going up against someone with a mix of both of her parents powers. Also noticeably we see her starting to combine inventions she's already made into bigger more powerful inventions, much like the Kludge did back in the second book. Not only that, but many of her designs as Pennultimate have a clockwork theme, right after she spent a lot of time in space observing interacting with the clockwork creations of the Jupiter colonists.
Even in the first book, a few moments after meeting Cybermancer whose "power" is his understanding of how technology and magic can be blended together, Penny comes up with a brand new way to blend technology and magic and creates the formula for the "curse grenades" we see him using later on.
Given he's described in the first book as one of the supervillains who always tends to succeed/win he probably used some of that money to hire her private tutors so she didn't have to go to public school and end up suffering Freakiness Shame.
Also consider the following sayings about how it is bad luck if a black cat crosses your path, and if you break a mirror it is seven years of bad luck. So imagine just how much bad luck you're going to end up with if breaking mirror (Mirabelle) causes a black cat (Entropy) to cross your path!