My sister likes my crush

For the past two years, I have had a crush on this guy named David, who is my friend's older brother, so just recently I found out she liked him and told everyone but me, even after that, she still didn't tell me. I found out from my cousin, not her!!!! Afterwards, she knew I liked him, so she told him, and he likes her back. He asked for her number she gave it to him he wants to date her so yeah. "good for her"