My book stumper is 2 books I’m pretty sure are in the same series. Both feature a main character who meets her doppelganger who has magic powers. In one they are at the pool in the summer and the main girl is afraid to jump off the high dive. In the other they are at the girls middle school and she wishes to fit in. She ends up making her own trends that catch on where people wear gypsy skirts with tank tops and padlocks on their belts. I’ve googled everything I can.