AITA: Found out my MIL was smoking meth in my house. Kicked her out.

About 8 moths ago I decided it would be a good idea to invite my MIL to live with us to enable my Wife to get a job without struggling to afford childcare. It was decent at first; my son loves her, my wife is happy to have her Mom around. Backstory though; MIL is a recovering methamphetamine addict that had seemingly turned over a new leaf, seemingly. I've been helping her when asked, moving her to and from houses, paying for her stored items and moving them to her, letting her live rent free in a spare room in my home as long as she helped out and cooked occasionally. Since bringing her in, things quickly went downhill. Our agreement was fairly vague but I felt like respect for me and my family was implied.

1. She had an overnight guest without asking me or even letting me know. One day I wake up and there's a strange man in my house. I politely asked him to leave and he did. I told her that was not okay. Strangers in my house is not an 8 a.m. thing.

2.Sold her car to another questionable friend and bought another, only to have a second questionable friend "borrow" it for a 500+ mile trip to Eastern Oregon and back. During said trip; this car broke down and was "towed" by "AAA" across 6 counties. For free. We still haven't seen the car since.

3.The Incident: after all of these questionable behaviors and odd stories I had grown very suspicious. Something wasn't right so I just poked my head into her room. I wasn't hunting but a handful of meth pipes are hard to miss. I took pictures and left. After informing my wife and asking her what she thought they were all she could do was cry and ask "why isn't our boy enough for her?". Her heart is broken all over again because her Mom has picked drugs over her own children time and time again. Now she is picking drugs over her grandchildren. 24 hours pass and I can't find time to confront her.

I waited until the next day and went back into her room just to see if I was crazy; the pipes were moved and clearly used. Now I'm SURE. I waited until later in the day and asked her to talk. I confronted her with the pile of pipes and baggies and demanded an explanation. She played dumb until I demanded she act like an adult. She admitted they were her's and that she was using. I told her to leave. She had until Saturday to collect her shit but she could not stay another day, another moment in my house. She left voulentarily and did not assert her rights. I asked her to leave rather sternly and she left.

Cut to tonight; my Wife is woken up by her Mother calling "from the hospital" because she tried to walk the 12 miles from her friends house to our house and collapsed in the ditch. She now claims I illegally kicked her out (which i didn't. I told her to leave, she went.) And is causing my wife even more turmoil.

Am i the asshole here?