Once again OP, you haven't said anything that suggests she wanted to take over the whole day...apart from you saying 'she wanted to take over the whole day'. What you have relayed in terms of what she has actually said does not suggest that.* I can only go on what you've* told us.
The problem is that like a PP said, this thread has become pretty polarised apart from the odd post here and there. You are entrenched in your view that MIL is manipulative and controlling and where there is no direct evidence of that, you will project and persuade us all that those are her intentions because that's just what she's like. In return, I'll admit that I have become inclined to think that everything you say about her is biased against her.
The truth, like most things, will be somewhere in between. She probably is a bit of a pain, isn't as 'hands on' a MIL as you'd have liked and is used to getting her own way, particularly with matters involving her son. You in turn are probably also used to getting your own way, think your own parents make better GPs, and are unwilling to compromise to make MIL's life easier because you don't see why you should.
Ultimately this pattern will continue unless you find a way to 'live with' each other, because like or not, you're related for life.