I got that I didn’t keep my agreement to reply as promised.
Re: “I don't know what else to do.” I get this. You’ve taken these relationships as far as you can using your present leadership-communication skills. If you keep communicating/relating as you have the problems will only escalate, and you'll be teaching your children how to create similar outcomes.
My initial thought was for you to invite your mother to a luncheon during which you could get all of this out. This is important because you’ve withheld some thoughts from her, which further exacerbates the problem. Mother needs to know the effects of the way in which she’s been treating you and of empowering your sister-in-law’s misuse and abuse. You could then tell her you've solved the problem, that you'll be getting your own sitter.
Now’s here’s the problem: Even if you clear with your mother it won’t address the source of your problem. I wouldn’t advise you to try to do a "clearing/luncheon" with your sister-in-law, unless you need more validation of your addiction to abuse and to being a victim.
Your parents were supposed to have taught you what to do when you encounter a person who is addicted to dividing so as to conquer. Your mother is unaware that she is creating this mess, for as yet some unacknowledged childhood incomplete with her mother. She's set you and SIL to mirror herself.
It appears that you have not discussed this with your brother. He needs to know what’s been happening, the effects of his leadership-communication skills, and that he has been empowering his wife to treat you abusively, from what I gather, to use/misuse your mother. That he is oblivious indicates that he is dragging around several nonverbalized resentments (most from childhood) and so he is using his wife to punish you and your mother. Brothers and sisters who are complete, who are experiencing loving support simply don’t have this kind of stuff between them. That he would marry someone with such beliefs communicates there's lots of incompletes between him and the whole family. It's not nice to bring an outsider into the clan who doesn't love everyone as much as he does. She is supposed to be honoring and supporting his family not creating messes.
Part of the problem as to why you have created this situation is to master communication; it has to do with the fact that you have taken on the valance of your mother, you’ve assumed her "nice," & "polite" act which sets it up for others to use her (a classic victim act). While it appears that she’s doing her daughter-in-law favors, in truth she is setting her up for undesirable consequences. DIL is supposed to arrange for her own sitter and only ask in emergencies and wait for invitations from your mother Most certainly your SIL has not compensated your mother in chores, gifts, or money. This is called using. It cannot but teach DIL's children to use others.
Re: “Moreover my nephew can be very hard to handle.” It appears that your nephew is already dramatizing this friction and unconsciously misbehaves so as to draw outside attention to the fact that his parents are out-integrity, that they need counseling. He remembers, way back, when things were harmonious between his parents. Now it hurts to be witness to this turmoil, this condition of out-integrity.
I don’t get that you’re ready yet (it hasn’t gotten bad enough) to commit yourself to abuse-free relationships and so you will continue to create these situations. There’s a saying: Ages 1-18 parents raise us, 18 on we raise them—until they allow us to make a similar contribution—after which we raise/support each other. It’s your turn to train your Mom. When you try you’ll discover that she will dramatize her upsets and have temper tantrums and play take-away just as you did with her. You have to be committed enough to her health (this stuff detracts from her aliveness, her very health) to send her to her room without supper if necessary. What this would look like is: “Mother, let’s do some counseling together, just you and I." She will of course decline (for reasons) your invitation. Then you’d deliver in writing: “Mom, the way I’ve been relating and communicating with you and SIL has been causing me upset and distress. It’s not healthy of me to submit myself to more abuse. I’m going to take a sabbatical from you for about six months during which time I’ll be doing some counseling and coaching. I’ll not be interacting with you except for emergencies. You can help me by doing 25 hours of therapy or counseling. I’ve got to improve my leadership-communication skills else I’ll end up teaching my children to create these frictions.” Parents have no idea there’s a whole new curriculum they must address to be supportive grandparents, else, they pass on their addictions to their grandchildren.
Last edited 4/19/16