These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Fair for Its Day: The series was actually comparatively feminist by the standards of the time — especially "Jo's Boys", which is set in a co-ed college, struggles openly with the concepts of gender equality, and comes to some surprisingly modern conclusions. In particular, Annie aka Nan is portrayed as a capable and independent woman who, despite caring for Tommy as an old friend, views him bringing up their Childhood Marriage Promise with open amusement, choosing to pursue her medical studies instead and ending up a successful single doctor — all the while Daisy's own choice to marry her Victorious Childhood Friend Nat and become a House Wife is also seen as valid and worthy of respect.
Fridge Horror: Mr. Laurence gives Beth his dead granddaughter's piano. So...Laurie had a sister or cousin?
According to some versions of the book, Laurie had an older sister who died when both of them were little kids. It's not said how she died, but it may have been an illness since Laurie himself was kind of an Ill Boy as a child.
Bhaer: But I have nothing to give you! My hands are empty!
Jo: (taking his hand) Not empty now.
"I know I shall be homesick for you, even in Heaven."
Hilarious in Hindsight: An out-of-universe example in Alcott's journal about her publisher's request to write a book for girls (info in brackets added by troper):
Marmee, Anna (Meg's real-life counterpart), and May (Amy's real-life counterpart) all approve my plan. So I plod away, though I donít enjoy this sort of thing. Never liked girls or knew many, except my sisters, but our queer plays and experiences may prove interesting, though I doubt it.
(Added later after the novel's publication and success) Good joke
Hollywood Homely: Most, if not all, of the movie adaptations cast very beautiful actresses to interpret the self-described "plain" Jo March, leading to the unintentionally hilarious moment when Jo has her hair cut off and a very shocked Amy cries: "Jo, your one beauty!". The Winona Ryder version even has her declare that she is "ugly and awkward". At least Katharine Hepburn in the most famous earlier adaptation isn't a classic beauty, and manages to make young Jo coltish and a bit clumsy.
This could also be said of the latest incarnation of Professor Bhaer, aka Gabriel Byrne.
Misaimed Fandom: Alcott was upset to see her female readers focus less on Jo's struggle to be a writer and live her life the way she wanted to, and much more on whether she and Laurie would or not end up married. Hence why her Ship Sinking was so determined.
"Girls write to ask who the Little Women will marry, as if that were the only aim of a woman's life. I won't marry Jo to Laurie to please anyone."
Purity Sue: Amy grows from a vain, spoiled, pretentious, tantrum-throwing little girl into the unabashed epitome of tact, taste, beauty and gentility as a woman, with next-to-no warning. Partly understandable when you realise she was based on Alcott's own younger sister May, who died after the book was published and left her daughter Louisa to be raised by Alcott. Also, Amy is kept deliberately in the background of the sequels, and is described as someone who doesn't seem to age — as a way for Alcott to remember her dead sister and cope with her absence.
Beth is so sweet and kind and is the only sister with no apparent flaws, aside from shyness and low self esteem. She always had elements of Sympathetic Sue as well, even before she became an Ill Girl. Her real life counterpart died, too.
Daisy is described as Beth incarnate in the end of Little Women and reminds Jo of Beth again in Little Men. Arguable, since while she has Sue-ish qualities she doesn't seal the spotlight.
The "Princess" Bess in Jo's Boys, which none of her fellow characters would ever try to deny.
Shipping Goggles: Jo puts on her Beth/Laurie shipping goggles in the chapter "Tender Troubles."