You can't step inbetween

I don't have any knowledge of the know-how in getting Chris' mom to kinda, back off. Since the whole thing with his injury I've eased my way back because they always manage to schedule appointments for his doctors when I have to be at work. And it's not like my schedule changes week to week. it's the same 4 days. Same 4 hours on those 4 days. So what gives. And I can't ASK for the doctor appointment to be fixed around MY schedule. Because it feels wrong to do something so selfish.
This injury is his fault; I feel that way strongly. He doesn't take care of himself. He doesn't understand the consequences of the things he does in life. Doesn't it bother him that he can't play with Jaiden? That he can't do much of anything.

So throughout this process, his mother has been his chauffeur to and from doctor visits which could be scheduled at any given time. She drops off and picks up his prescriptions. And as I'd come to find out they plan on talking to a lawyer about suing the other driver's insurance company for any bills pertaining to Chris' accident and medical statements, she'll be taking him to that too..

She goes on and on about how he should get his affairs straight, handle his bills, or at least let me do it and then she turns around and just pays it for him. Like it's just THAT easy. Write a check. Take care of it all. BAM.

I just hate that she's always around now. I can't stand it because she's never up to much good. She steps on my toes and acts in a way that she feels I won't trace back to her, not that I'm looking for a path back to her. Not to mention when she's doing all this crap for him, I have to either rely on both her and Chris to take Jaiden and make sure she eat OR they have to be back in time for me to go to work. On almost every occasion, either Chris, her, or BOTH have been late arriving to pick up or get ready.

SO I'm getting jammed either way.
I haven't been late to work yet but it's bound to happen.
and I can't say anything because I'll be the wrong one. The one inbetween.