What does this sound like to you?

My son is in prison (he went may 2010). He'll be getting out this summer! His girlfriend use to call me all the time and I haven't spoken to her since november 2010. Last month I left her a message telling her to call me. She called me and I ask have she heard from my son. She said yes he wrote her the other day! I wanted to ask her a few more questions because I heard she's messing around with someone else she act like she was in a rush to get off the phone so I told her to call me back in ten minutes, she agreed! Guess what? She never called so I called her and she never answered her phone. What do you guys think is going on? Remind you I haven't heard from since november. I left her a message on facebook to call me. She was in a rush, didn't call me back in ten mintues and didn't answer my call. Its been a month since this happened and still nothing! But she said my son is still writing her (what's going on)? Something isn't right because she called me all the time! Hmmmm??? What do you guys think? DETAIL.