Tom, your sister saying she's isn't going to participate in a family call to uncles she hasn't spoken to for years because of a need to guard her mental health doesn't come across as selfish at all.

There are often reasons people choose not to talk with relatives - especially why women might refuse to talk with older male relatives.

I'm not saying your sister was abused - but I am saying that, if she was, your reaction makes you an unsafe person for her to share that with and would explain why you got a vague answer for her saying no.

I encourage you to trust that she knows best what she needs to do to guard her mental health and work on her healing.