I disagree...I think it's about class. Not because there are not women like Elizabeth. To phrase it shortly...there weren't women like Elizabeth...in the same class as Darcy, they were not taught to be educated and independent minded. They were taught to agree with their husband, play music, be beautiful, and be docile but competitive to their own sex to defend the reputation of their husbands. Lizzy knows this, she knows why she is a fish out of water, and she points this out to Darcy in a veiled demeaning statement about his "friends".

That the circumstance of womenhood that I imagine Austen was critiquing in her own life was just something predictably not Lizzy. I don't think she saw herself as anything but another middle income girl who read a lot of books probably at the end of her families wealth climb and her sister hopefully marrying someone rich so she can be prosperous. She likely does not feel she has value outside her intelligence due to the shadow of her sister and the way society sees them. I don't think she thinks she is "not like other girls" but she knows Darcy doesn't have the chance to be around other girls....and her breed in general IS RARE...because of the state of opinion at the time around women and education.

Whereas I think the modern context of "not like other girls" is just different. It's not about class, it's about narcissism and lack of awareness, in a time period where MOST GIRLS in the context these women are "othering" themselves...are very much just like them, only aesthetically chose something else. IE: Anime instead of Reality tv, books instead of social skills, etc. Generally superficial things that don't denote intelligence or substance of person.

I think she merely mentions women in the context of courting not as if other women are different. She's specifically assuming he's only courted other rich women from established families who were groomed in a manner as objects to be used as currency in familial exchanges and made to be desirable in obtuse ways...flattery and charisma over intelligence, wit, and tact.

Elizabeth is from a minor family...her parents didn't intend or teach her to flatter and kowtow to men because they have a different context and she wouldn't gain much of it and they really didn't NEED her to be anything, they had MANY daughters. Hence, she assumes Darcy likely has never interacted with a women like her because he likely doesn't talk to lower class people AND CERTAINLY would not ever be assumed to be courted by anyone but someone close to his class and stature...let alone a women who was allowed into her fathers study to educate herself.

She was born in a house of women and not the eldest of middle income (possibly lower-middle even though the middle class barely existed and wealth disparity and lifestyle between "upper" and "lower" was an insurmountable chasm). Their family didn't raise her in that way and allowed her the rights of a man (to read and enjoy education fully) because the rules of society really didn't much apply to them in the same way with the same weight. So to meet a girl like her was likely exceedingly rare for Darcy and hence his general distaste and distrust in their initial encounters. He's jaded. She knows it.