Best Teen Books discussion

Hi! I have been wracking my brain trying to think of a book I read a few years ago (published between 2010-'18 I think). Here's what I remember:

YA mystery with magical realism elements about a girl in private school in Brooklyn (Park Slope maybe?) who gets pregnant and thinks she was impregnated by the sea/water. I think the girl's name is in the title. I remember the cover being soft pinks and dark blues.
Thanks in advance for any ideas!

Could it be The Inconceivable Life of Quinn by Marianna Baer?

YES!!! Wow, thanks so much. ✨