Should I do it?

So this girl i’ve been friends with lately we haven’t talked in months because of me. She was solely focused on another friend and wouldn’t pay attention to anyone else but would invite them. So we would all feel left out and I do miss her and it’s her birthday today and I’ve debated on telling her happy birthday but i haven’t talked to her in like 3 months so idk if should just randomly say it. She has asked about me and has asked if I hate her and it’s not that. It’s just she isn’t really a good friend because she just focuses on one person every time instead of everyone else. She would blow me off for someone else. But since she’s been asking about me makes me feel like maybe she’s trying to become better friends with me. But idk.