Haven’t talked to her in 5plus years

Ok so me n my former best friend which we haven’t talked or anything or went out n 5 plus years there bday arrived a few days ago.. n there having a party or seafood boil or something i noticed they post on her social media ..& she inbox me n says was i free tomorrow evening i replied what’s going on tomorrow?

Idk how to go about that we hardly talk any more n u pop up n invite me to ur gathering ... i posted on her wall happy bday few days ago n she didn’t respond but she inboxes me few days later 🤔🤔