You have a match / Emma Lord.

"A new love, a secret sister, and a summer she'll never forget. From the beloved author of Tweet Cute comes Emma Lord's You Have a Match, a hilarious and heartfelt novel of romance, sisterhood, and friendship... When Abby signs up for a DNA service, it's mainly to give her friend and secret love interest, Leo, a nudge. After all, she knows who she is already: Avid photographer. Injury-prone tree climber. Best friend to Leo and Connie...although ever since the B.E.I. (Big Embarrassing Incident) with Leo, things have been awkward on that front. But she didn't know she's a younger sister. When the DNA service reveals Abby has a secret sister, shimmery-haired Instagram star Savannah Tully, it's hard to believe they're from the same planet, never mind the same parents--especially considering Savannah, queen of green smoothies, is only a year and a half older than Abby herself. The logical course of action? Meet up at summer camp (obviously) and figure out why Abby's parents gave Savvy up for adoption. But there are complications: Savvy is a rigid rule-follower and total narc. Leo is the camp's co-chef, putting Abby's growing feelings for him on blast. And her parents have a secret that threatens to unravel everything. But part of life is showing up, leaning in, and learning to fit all your awkward pieces together. Because sometimes, the hardest things can also be the best ones"--Provided by publisher.