I think you're making too much of the phone incidents. Phones DO get fixed or replaced, you know. What kind of proof do you have that makes you suspicious that Jayce doesn't like you? If you have no proof, why are you suspicious? Don't read too much into things, or you'll drive her off. No one likes someone who acts suspicious. Then that person feels like you're too "needy." That will drive them off in a heartbeat. Jayce sounds smart enough to not pay attention to what her sister thinks, so I wouldn't worry about that.

I'd just continue the way you have. Keep talking and having fun. If it doesn't work out, then it just wasn't meant to be, right? Good luck! Hugs, Lee