My mother inlaw comes with a lot of baggage and isn't the most stable of people. She constantly tries to help her daughter who then throws it all back in her face and she gets burned. She promises she will stay away from her but always manages to go back. It's exhausting. It's also putting a strain on my partner and I's relationship. He has a very short fuse and it's been school holidays here and I am looking after his daughter from his previous relationship. I do have to say we have been together for over 5 years now but looking after her and having the MIL here too is just making me feel trapped. 

We can't quite tell her to leave without her getting a place and I do believe she is trying but I think her being here is putting this strain on us. I don't know what to say to my partner as he is at the point of not wanting her here. 

Has anyone had to deal with living with their MIL for a period of time and know of any ways to cope with her and to not have the strain in my partner and I's relationship??

Sorry about being so long.