Help!my girlgfriend took drug,what should I do?

Tweet

I have been in a relationship with my girfriend for two months.Recently she took methamphetamine(ice,OR p)she said it was her first to take that drug.And she took another on for only one time before.Generally,she is a kind girl,she adopted three kids who are all orphans.Before she did that she had told me she promised her bestfriend to try a little bit.(they have known each other for 10 yeats.and her friend is a drug user for 5years.)i warn her not to do ,and she said ok,but she finally did.(I knew it by keep asking her.)She assured me it was going to happen again but somehow I just dont buy it.I have been upset about that although she keeps saying sorry to me .I dont know what to do next.should I forgive her or should I break up with her?beause she is not reliable and she can get drug from her best friend.