Jennifer Kelly Geddes

Shopping with girls of a certain age can be tricky. Take mine, for example—Isabel, 12, and Fiona, 10. They read Girls' Life and glance at People, but haven't a clue yet that Teen Vogue exists. They're itching to leave the sequins of the Children's Place behind, but aren't nearly ready to slip into Bebe's short designs. To split the difference, we visited four city shops to find out what's hot—and appropriate—for my future fashionistas. Berkley GirlSeven For All Mankind and Juicy Couture wares are stocked alongside quilted overnight bags and sporty wristwatches at this UWS fave. The owner, Jen Bruder, uses a local focus group to gauge the best tween trends—and it shows. Nearly everything the girls picked up was a hit, from flapper-like dresses (just right for upcoming bat mitzvah season) to sweet—but not babyish—bathing suit cover-ups. 410 Columbus Ave between 79th and 80th Sts (212-877-4770, berkleygirl.com)Top picks Isabel was all over a GLEEK sparkle shirt ($43); Fiona went for the Mogo magnetic bracelets ($14) with add-on charms ($4 each). InfinityThe boutique carries a number of popular tween brands (Butter, Littlefox), but offers a more individual touch: free alterations and a "crystal bar" where kids choose sparkly designs to hot-press onto purchases. Some of the sequin dresses seemed a bit over the top, though a black and silver romper was universally applauded (very Willow Smith). 1116 Madison Ave at 83rd St (212-734-0077)Top picks A bathrobe printed with sushi ($70)