Here is a very bad thing to say: “I just don’t know what goes on in (insert gendered pronoun here) head. What in the hell were they thinking?!“
Here is what would make that very bad thing to say even worse: the gendered pronoun in question is a member of your immediate family.
Vague, I know. I’m just thinking out loud. Or, in this case, thinking in text posted on the internet for anyone (and their immediate family member) to read.
Family is hard.