Well - I'm not an expert but love a good book, particularly women's history.
I have to say that recent books are depressing 
DP (genuinely trying to cheer me up from all this) bought me Dorling Kindersley's Women - Our Story. Beautiful, lovely illustrations and, tbf, mostly knows what a woman is. The last bit... Lili Elbe was a woman...
Also DK The Feminism Book. Worse. Also, I liked the writing style much less - for me, it was very dry.
They also have Feminism is. I've only read the sample - very pacey and readable, but again, doesn't look good on trans.
I had a rant on the new ed of The Women's Atlas recently. I've since gone back, and should say, that for the most part, it's talking about those boring old bio women. Well-written, and such a classic. So, I'd say a good read with a bit of caution.
Virago? To be blunt, I could weep. I Call Myself A Feminist, 25 Women Under 30. Don't.
Jenni Murray's two history books. I have the world one. Fairly slight, but very engaging, I think they'd be very good for a bookish teen and, of course, she knows what a woman is.
Good luck!