"sorry your marriage failed" in that snot-nosed spirit is hardly an opinion per se, and sarcastically mocking your parents' marriage to the world--even if she is only 15--is a pretty cunty thing to do. Speaking of 15, I can see a beautiful bouncing mulatto addition to the Conway household in 2022. : )
15 year olds are cunty. They have half baked views formed from their limited experience of the world, they're hormonal and over excitable and generally hugely irritating. I've been a 15 year old, which is why I know I want nothing to do with them 30 years on.
I'm just sympathetic to the thought of someone having to be one in the public sphere of that family, and I think it's massively hypocritical to say "leave Barron out of it" at the same time as "she's a disrespectful guttersnipe".