My sister gets into toxic fights with my mother. How can I help? | Ask Annalisa Barbieri

The first priority must be the safety of the most vulnerable – your mother and your sister’s children

• Every week Annalisa Barbieri addresses a problem sent in by a reader

I’m a 40-year-old man and worried about my family. Since my sister (in her late 30s) became pregnant with her first child four years ago, there hasn’t been a period longer than a week without her and my mother getting into toxic fights.

A couple of days ago, after my sister had resorted (yet again) to calling our mother names, she also ended up grabbing her by the throat.