Responsibility for Siblings

I personally think it’s a big mistake to give a child the responsibility for their sibling, even if it’s only implied. (It’s actually a pet peeve of mine.) If she is having issues with him, if she feels like (even if you’ve never said) responsible for him or if she feels crowded out by him, or bothered by him, I think it would benefit you all to try to keep them separate for a while. She needs to have her own private space for her stuff and her friends away from him. I am sure that on some level she felt replaced by him. Even though she is the big sister she needs to be treated like the little kid she still is too. Nine is still pretty young. Your dd didn’t order a little brother to take care of or be followed around by and even if she thought it was a great idea at the time, she was too little to make that decision and know how it would affect her. If she had enough space of her own and attention for herself, she wouldn’t feel the need to be mean to him in a sneaky way. It sounds like her cup is not full on an emotional level.

Angela S. (game-enthusiast)

Sandra Dodd:

Some older children are as happy to sleep with a brother or sister as with a parent, but please don't require one of your children to comfort a sibling all night, nor to be responsible for the safety of a younger child. It's too much to put on a young person, and it will move you away from, rather than toward, parent/child bonding with both of those children.

Babies need parents all the time, not just during daylight hours.

from The Big Book of Unschooling,
that section in excerpt here