signs ex-gf wants to come back?

what are the signs than ex-gf wants to come back?
- I see her about 4 times a year and we were best friends before.
- she kisses me on the cheek after saying good bye.
- i know shes with no one now. she still acts the same when I was her gf and after as an ex.
what are the signs/clues though that she wants to come back or not?