Anonymous wrote:The time to intervene was in childhood.
It seems extreme that your cousin's failure to thrive and launch is the result of the sibling's abuse.
However it is their right to not want a relationship with the sibling.
The role of the parent and other family members is to respect that decision. Not try to talk or trick them into seeing the estranged sibling. As well as not being the go between, if they have things to say they need to say it to each other.
Anonymous wrote:Is one of these brothers your spouse?