Do you ever interrupt your siblings bickering with their partners by interjectin rude comments?

One of my elder brother is out of shape, he was involved in a motorcycle accident 6 months ago. While in rehab, he has put on 10 kg.

His wife continuously makes rude remarks about his weight during family gatherings. I see the humiliation on my brothers face and he’s very sensitive. I had enough, I went into the house and brought a standing mirror and told her to look at herself, she ain’t no oil painting and she’s twice his size. She left, my mother told me off and my brother gave me the longest hug and a big fat kiss on the cheeks.

Sadly she will probably unleash her anger on him. I’m not sure if I should apologise or leave it be.