Insecurity

My amazing girlfriend made some couple of questionable friends from work. We live in different states but have been trying to save up money to live together. Something that I wouldn’t bring up but is relevant to the situation is that my girlfriend is transgender and soon, her appearance from hormone therapy will take form and she’s thinking her grandma is going to kick her out. I’ve offered everything in my power to help her in case that happened, which she was very grateful for and we’ve tried to find an easier solution. Two of her coworkers who are in a relationship offered to get an apartment with her and share the expenses, which I was hesitant about especially since I wasn’t present, but I agreed that if it made the circumstances easier, then we can consider it. That all changed when my girlfriend went to the movies with those two friends, and they admitted to drinking & driving, took her out into a parking lot and did a drug deal WITHOUT informing her first, and then, had the audacity to talk about how they both had sex with a friend when they got drunk (after discussing drinking plans with my girlfriend.) They know she’s in a relationship with me, and my girlfriend was extremely uncomfortable and left and told me immediately. I’m furious, not at her, but just at the situation, and tried my best to not seem like I’m skeptical of her or anything. I’m furious that those two friends put her in that situation, but these are my girlfriend’s only friends in her area that accept her identity, however, I am absolutely certain that they are testing the waters to see if they can try to do something with her, which makes me and her uncomfortable. She said at the very least, she’s gonna set boundaries, or cut them off, but I feel like even if boundaries were set, I can’t feel comfortable with that anymore. Not because I think my girlfriend would cheat (even though my brain tries to get me scared about that), but because I feel as if those people will take advantage of her or try to do something. I just need advice to manage my emotions while still helping my girlfriend with this situation.