Lots of issues on your hands. One, without question it was a really dumb idea to let tenants move in without a sublease. Even if that shit is your mom, you do a sublease. There are even simple templates online, or common-sense agreements you can type up that would hold up better in court. Two, figure out your priorities. If you care about your GF, you'll side with her and not secretly question whether she's confused about the druggings or not. It's also completely unrealistic what you're asking of her, to go file a restraining order, that takes a lot of time and also takes legal proceedings to even get you there.. DO NOT subject your girlfriend to the dangers of getting police involved or filing restraining orders, you appear to not be nearly knowledgeable enough to advise her on the correct proceedings.

TL;DR - you need to hire an attorney now.