Hi! Asking "what should I do" is off-topic here. There is not much details to go on too. Can you tell us the reason behind their fight and the interpersonal skills issue you're having? — A J ♦ 31 secs ago

@Daniel Unless your grandmother specifically asked to do it without your mother's consent, the request is open to interpretation. I think that you can tell your grandmother truthfully and politely, with all sympathy, that your mother did not consent. Your grandmother will be hurt, so do not argue with her at the moment. Just respond with "I am so sorry grandmother". At a later date, if she faults you, you can point out it that the alternative may have been even more painful — yo9cyb 9 secs ago

I agree. A child's moral support is priceless for a mother. Just showing extra love to your mother, just telling her not to mind, is huge. — yo9cyb 2 mins ago

Asking "is there anything you want in particular?" is delicate, and does not serve the original purpose. you must be prepared to do it. — yo9cyb 1 min ago

@NepeneNep I see some problems with this answer. First, the OP asks specifically not to object to her parents' decision. Second, we don't know if this house is where the children grew up (and, as other people here commented, it's normal to have boundaries even with adult chidren). — yo9cyb 34 secs ago

@yo9cyb OP is in an awkward situation because their parents made a decision on their brother, not their sister. They didn't make a boundary with the sister, and so OP is feeling the pressure of an interpersonal conflict with the sister where they have to set up a boundary with their sibling on their parent's behalf. — Nepene Nep 1 min ago