If your sibling was being mistreated by their partner, or in what could be described as an abusive relationship, would you interfere?

I didn't/couldn't. I was just there for her, and praised GOD when she finally left him.

If it was one of my sisters you better believe I would.

No. My brothers have been big boys for a very long time and have been/was married for a long time (one's a widower). One has a very weird relationship with his wife but that's their decision.

Now, if a brother was incapacitated (as from an illness or injury) and there was mistreatment, then you bet I would.

I'll say something, but I wouldn't meddle into it. Ultimately, I have to let them make that decision for themselves.

My one sister was in a physically abusive relationship for 30yrs where they BOTH beat each other, would get restraining orders and then make up. I was on her side many many times giving her money for lawyers and supporting her in court... and in the end she never left him.

The other sister is married to a miserable version of Fraiser Crane who is very controlling and mentally abusive. When i tried to help her, it only caused more problems because she saw him as a person of social status and a great provider. She would not accept the fact that he was belittling and demeaning towards her. she is STILL with him after 20yrs.

I would totally interfere if it was out of hand.