Mother in law advice

Need some advice on what to do about my mother in law. Mil lives with me, my husband, and our two kids. The house belongs to us she lives in the room downstairs with her dog. There are a few issues but at the moment the problem is with mils dog. She is continually peeing in the house, on the rug in my husbands office and her room has gotten to the point where it reeks of pee and is making the downstairs stink. Mil hides in her room all day watching videos or playing games comes out like twice a day. She doesn't regularly take her out, she bought potty diapers but hasn't once used them yet. And claims it's because the dog is used to having the door open all day and just coming in and out. Well in the colder months we had the door open a lot during the day and the dog would still pee in the house but now that it's getting hotter we have flies coming out and I can't stand flies in my house and we run the ac during the day so having the door open would be a big waste of energy. Mil claims she was going to clean the carpets, I borrowed an upright carpet cleaner from my parents, it's been sitting there for 3 weeks now and she hasn't touched it..

other issues is she said she would help out with paying bills and she is super inconsistent about that. She moved in last October and didn't pay anything until January, not rent, utilities etc and took a loan from us as well. She's horrible with money but is retired and doesn't want to go back to any kind of work. Which I understand she's retired she wants to relax. But it was agreed that she'd help watch the kids occasionally which she does when I need to go run errand or someone has a dr appt. If she has to go get a job then I guess there goes the helping with the kids.

She has 2 cats that live in a catio in our backyard. We have a cat that lives indoors only. We asked her when she moved in that her cats remain outside because ours lives indoors and he gets stressed by other animals that he's not used to and it causes utis for him( he's even on a special food to help prevent them) but multiple times she has brought one or both cats inside..

My husband and I are both getting really fed up with her lack of respect for our house/stuff and just lack of motivation to do anything/keep promises she makes. We are essentially supporting her at this point.

The problem is, when my husband tries to bring up these issues with her, there's two problems. I think the way my husband sometimes tries to get his point out comes across a little harsh and mil is very defensive. She acts as if she's being personally attacked if we bring up something she's doing/not doing that is a problem.

So how do i/ we get the issues we want fixed without her shutting down/getting offended?

In all honestly we probably would have asked her to leave already but she has no where to go and no money to get a place of her own. Plus I feel like asking her to leave would be on the level of essentially severing all ties with her which is not what we want. We love her, she's a great person but we want our house/stuff to stay clean/nice and want our boundaries kept to