How to Deal with a Mother Who Over-Supports Her Siblings

Maybe you should look for clues in their childhood history. After all, this is your mother's own younger brother — one of her closest blood relatives. If your mother is significantly older than your uncle, there's probably some deeply rooted maternal instinct at play, something built up since they were kids. If it were you versus your father, your mother would probably be far more forgiving and patient with you than with your dad — many times over. And if this uncle occupies something like the role of a much younger sibling in your mother's mind, that could explain a lot.

The other angle to consider is psychology and personality. Every Zhou Yu has his Huang Gai — it takes two willing parties. Some people can only feel fulfilled by caring for specific people, and trying to make them "less burdened" is essentially cutting off the very thing that gives their personality a sense of purpose. One person's honey is another's poison.