I agree with all those saying speak directly with BiL and FiL and make it clear to themthat they need to speak to YOU, not to MiL, about plans which involve you or you home.
I think you need also to sit down with your hsuabnd and agree on how you are going to deal with his mothers behaviour. In one sense, it doesn't really matter *why* she is behaving in this way - the issue is about how you adress it. If your husband feels it is due to lack of emotional maturity then *he* can have a conversation (or many) with her when he explains that while she may not have intended it, her actions are inappropriate. But first, you and he need to agree on what the two of you will *do* and then stick to it.
This could be -
(1) any time MIL makes aragnemtns for you/your home without speaking to you, when she tells you what she has done, the response is "We've explained before, you can't invite people to our home / tell people they can visit us. You will have to call back BIL / FIL / Whoever and explain to them that you hadn't cleared this with us and that they will need to contact us directly" And if necessary, contact that person yourself and tell them that you're very sorry, but MIL did not consult with you before offering your home/services and it simply won't be possible.
The effect of this is that it puts the problem firmly back in her lap - she has to make the explanations, find the alternative arragnments. It may reduce the frequency with which she commits you without asking you, plus any 3rd parties are given a heads up that she is not authorised to make those pronmises or issue invitations on your behalf. (for family, I'd contact them directly, first, and ask them not to make arrangemetns with MIL which involve you. If they still do it after that then refusing to play ball, even if it means you miss out on a visit once, is likely to be worth it in the loger term)
(2) Re: 'leaving her out' of trips etc I'd go with the faint suprise approach
Her "You went to see Avengers and didn't invite me!Why did you leave me out"
YOu / DH *faintly surprised tone* We didn't invite anyone. It was just for DH & "
Her "But I wanted to see it!"
You/DH "You should invite some of your firends. Or you could look into joining a film club"
Don't make excuses. Don't give her excuses.
It might be helpful if DH sits down with her and tells her, clearly, that while you are happy to see her, you will invite her when you want to do stuff together, she can invite you if she would like to do stuff together (but you may not always be able to accept) but that she needs to understand that you have your own lives, and that is being unreasonable. He can remind her of that conversation everytime she makes an unreasonable demand. The key is that you and he are both firm and don't cave in just because she makes a fuss.
You could, if you wish, find details for her of local clubs or groups she might be interested in, if she hasn't made many local friends, but this is not your responsibility.