How can i handle this?

wait and give her time before calling 911 or anything, if it turns out nothings wrong it would be a waste of the police's time and probably get you in trouble. it may be that she has no internet, or that since she just moved she hasn't had time to get on yet ect. if in a month or so neither of you have had any contact AND the girl's mother still won't tell you what is going on AND you can't get her number in anyway (if you can find his name and general address do try to look it up on the internet or in a phone book) then you can take more drastic measures. until then wait it out, there may be a very good reason for all of the things happening, including why she didn't tell you and her mom won't talk about it. i hope you hear from her and everything works out well.