Why is my mother-in-law living with us when she doesn’t have to?

Of course it's not 'normal', especially at 64 years old! I'm 65 and the thought of doing such a thing to any of our children is beyond ridiculous.

She's doing this because she CAN and nobody's telling her she CAN'T.

And somebody had better tell her she's got to get out before her $200K in retirement savings is down to $20K in retirement savings and she really IS broke, the way things are going right now. No joke.

It's time for your partner to grow a spine and tell mama it's time to get OFF the couch and on with her own life, elsewhere, and out of your home.

Why are you staying with him? He has clearly chosen his mother as his life partner, not you.

Leave as soon as you can. Seek counseling to learn how to make better choices in mates.

I think that you need to have a "sit down talk" with your husband.
(Actually reading your post again this is not your legal husband (unless where you live recognizes common law marriage))
You can begin packing up your things and look for a place of your own. (Or a friend you can stay with for a while.)
If you have children together talk to a lawyer first about support for them. If the kids are your partners then they become his full responsibility.
Pick a move out date and move. Let them live together for a while and see how that goes.
You should not have to put up with disrespectful behavior from her.
If you want to continue a relationship with your partner you can start again by getting to know each other, date and let your feelings be known.

Astridlux, sounds like you need to post on a marriage therapy website. This doesn't sound like a caregiving issue, as your partner's Mom doesn't need that type of help.

Is your husband an idiot? How do you know all about her finances but he doesn't?

Your partner has prioritized your MIL over your relationship. He/she can deny it, but the facts speak for themselves. Your partner needs to decide. If partner says he/she chooses you, then partner must prove it by moving out Mother by _______ date (and don't drag it out very far). FYI your home is now her legal residence, and if she refuses to go, you will need to go through the eviction process. You apply for the form (and pay a fee to file it) at your county's courthouse. In most cases she will have 30 to move once you post the notice in the way specified on the form.

Next, you have chosen to post on an aging/caregiving related forum. Does this mean you suspect that MIL may have a cognitive impairment? From the info you provided, it sounds like her non-sensical decisions on every front may indicate she may have something more going on, like Alzheimers. I have a 68-yr old cousin who was recently diagnosed. She marrried a dopey guy 20-years her junior, and made all sorts or weird decisions about selling her home, moving, then moving back. It made no sense...until she started getting lost driving to places she was very familiar with, and not taking herr thyroid meds correctly, and it finally got so bad they had to trick her into going to a doctor (about her thyroid) but then asked for a cognitive exam, which lead to further exams and the final ALZ diagnosis.

Your MIL is not too young to perhaps have this problem -- especially if she wasn't like this until recently. If you think this may be at play, then you and your partner need to discuss what your plan going forward will be. But if I were in your shoes, I'd get her in for an exam before kicking her out. That's just me...other responders may disagree but it would be cruel to kick out someone who is no longer medically capable of acting in their own best interests. I wish you much clarity, unity and wisdom as you sort through this.

Of course she doesn’t care! She’s living there for free and doesn’t have to lift a finger.

Next time you have to call 911 on her, Let them take her to the hospital. Speak to a social worker (or anyone who will listen!) and tell them she is not safe in your home and needs placement in a facility. You are in no way responsible— legally or morally— to house her. They will argue and try to convince you to take her back home. Do not give an inch!

Your kids aren’t safe with her either. And it has to be stressful on them to have this insane drunk woman in the house.

If your partner takes her home anyway, then it’s time to go elsewhere with your kids. I realize this is easier said than done. Let him take care of ol’ mama and the house alone for awhile.

He has to make a choice. Mama or his own family. If he chooses Mama, you’re better off without him.

Why? and how? have you and your husband coped with this for over 2 years? Why does your husband tolerate her getting drunk and spitting on the floor in your house? Why did you get an ambulance when she was drunk – that’s not what an ambulance is usually for! How is the marriage going, if he “becomes passive aggressive and mean just like her and he starts to talk about me and how I am and I’m the problem”?

None of this makes sense to me. In fact it sounds too horrible to be true. Have you tried to get help for yourself? Or for the kids who get a mention in passing? If not, why not?

When you and your partner fight due to the stress of mil being there, what does he say? That she must live there because she is broke? What does he say when you point out that she has over $200K in a bank account?

Because someone let her in, presumably. Much like the noble cockroach, if you let elderly relatives infest your house, it's a significant challenge to get rid of them.

The smell is oddly similar too...