I think my gf is doing drugs

I think my gf is doing drugs

I'm gonna try to make this short, but I realize context is needed.

My gf (28/F) is currently in Giddings and I'm (M/36) in El paso. She is with her mom right now because my finances have crumbled due to me getting injured on the job and then losing said job. I told her I wanted her to move in with her mom in Giddings with the kids because her mom agreed to help out. Her goals were to get a job there and help with finances until I could get everything over here stable again.

She's been hanging out with a friend she knew from High School. I didn't know too much about her and I tend to keep it that way, because I don't want to be bias about someone before meeting them. The girl was cool, but....off. She jokes about drugs ALOT. One day, the topic of mushrooms came up and she immediately started talking about the good experiences she had with shrooms. She then said, with a serious tone, that she had some and her, my gf, and I could all try some and have "a blast".

For some context; I hate drugs. My whole life, I have seen nothing, but the cons of drugs. It destroyed both my sister's lives and is the reason my dad and uncle are dead. Friends of mine have become homeless tweakers on the corner because of drugs. I have a zero tolerance for drugs. The only exceptions are cigarettes, alcohol, and weed, and that's only if done on occasions. In other words, I don't tolerate alcoholics or everyday stoners (unless it's for medical reasons).

Anyways, I brushed it off and said, "No, I'm good." my gf did the same. I got off the phone with her for a few hours and then, I'd say around 3am, she called me. The way she spoke was....different. And when I mentioned it, she became defensive and angry and we got into an argument. It was not a good night.

The next couple days, she was very easily agitated and she would keep screaming at me about how I wouldn't communicate with when I would try to bring up some of these issues of her suspicious behavior. I was always calm and respectful and tried to assure her that all I wanted to know was what was going on with her, because she was acting differently. We would video call and her behavior was strange as well. She would have this spasm in her right eye and then use her hand to stop it. She would also randomly jerk her head to either side, like you're trying to look at something as quick as possible. Through my experience, this is the behavior of someone who does amphetamines.

I asked her if she has done any drugs and she would tell me, "No, I'm just tired and have a migraine from allergies."

Mind you, we have two daughters and they are both over there with her and her mom. However, during this time, the kids were with her mom and she was with her friend. This has been going on for about 5 days now and some days she will even stay the night there.

I am genuinely concerned and suspect that her and her friend are doing drugs. I'm not sure what to do here.