Maybe you want good book ideas for a niece, daughter, young friend or expecting mama. Or maybe you actually want some good feminist reading for the -- gasp -- boys in your life. Regardless, you should check out the Amelia Bloomer Project, six years (and counting) of book awards to "honor the authors, illustrators, editors, and publishers who give life to books that encourage readers young and old to push the envelope and challenge what it means to be a woman, regardless of ethnicity or social-economic background."
The list includes both fiction and non-, from beginning readers all the way through young adults. To my eye, it's a little heavy on biographical nonfiction -- but then again, that's kind of a nice corrective to the Caldecott and Newbery awards, both of which emphasize fiction. And given that elementary education still emphasizes dead white males, it can only be valuable to introduce girls and boys to real feminist heroines. The list also tends to emphasize stories that celebrate determined women overcoming explicitly sexist obstacles; depending on your approach to nonsexist child rearing (and the age and temperament of the kids you're buying for), the Amelia Bloomer Project's definition of feminist content might seem a little didactic.
But given that even today children's stories continue to rely heavily on male protagonists (Harry Potter, anyone?) or to emphasize girly girls ("Fancy Nancy"), a certain amount of sober-minded reading and a reminder that feminism's about more than pink "girl power" T-shirts can't hurt.