Can a person smoke crystal meth for a few months and then stop without intervention and not be addicted?

I am worried about my 25 year old daughter. We were told by one of her friends, who has gone into a recovery program, that our daughter smokes crystal meth. She doesn’t know that we know. She still lives at home w/ both parents and a 20 year old brother. She was diagnosed as being bipolar & ADD. Her father and I have never seen the “real her”, so it is hard to know if it’s drugs or being manic. We located a live-in recovery home w/ 12 step program & is linked w/ a great church. We were going to do an intervention but now we don’t know if she is still using, since she has been better the last few weeks. It will soon be Christmas & we thought it would be better to wait after the new year. She has always been secretive and never really talks w/ us, also she lies constantly, so rationally talking to her isn’t possible. She uses confrontation to make any such communication impossible. Could she have stopped using? Do we need further proof of her drug usage to send her to a recovery program?