When the protagonist of Speak, Melinda, sees a card on her locker on Valentine's Day, she feels conflicted. At first, she thinks it must be someone playing a trick on her and for a second even fears it's from her rapist, Andy. But then she starts to suspect it might be from her lab partner, David Petrakis. It seems like she's hoping it's from David. Melinda has admired him in the past for standing up to Mr. Neck about the immigration debate and he seems like the kind of motivated but sweet guy who would be great for Melinda. She is initially too frightened to open it, though, and heads for biology.
In biology, she and David pass a notebook back and forth a couple times, making a doodle on it together. Melinda doesn't say anything about the card, in case it wasn't from him. And it's a good thing she doesn't, because it isn't. It's from Heather:
"The card has a picture of two cutesy teddy bears sharing a pot of honey. I open it. "Thanks for understanding! You're the sweetest!" It is signed with a purple pen. "Good luck!!! Heather" (pg 110).
Yes, the same Heather who "broke up" with Melinda as a friend and told her she needed professional help. She also included the half of a "best friends" necklace Melinda had given her. While Heather probably means this to be polite and friendly, it comes off as ice cold and makes Melinda feel horrible and lonely.