Dear Prudence,
I am moving temporarily overseas. Since summer is coming, I thought of inviting my two nieces to come visit. I would pay for the plane tickets. One is in college and the other will be starting high school. My brother is engaged and his fiancée is particularly pissed off that I didn’t think to include her 17-year-old daughter in the offer. I accidentally overheard her talking with my brother; he forgot to hang up, and she was saying nasty things about me over this. I have never met this girl. I only met the fiancée this Christmas for a few days at our parents. I was happy that my brother found someone, but this reaction is so bizarre and out of left field that it leaves me stumped on how to proceed. Do I talk to my brother about it? Ignore it? Bring it up to my other two siblings (parents of my nieces)? If my brother wanted to bring both of them on a trip to visit me, I would be more than happy to host. But only if he was there. This entire situation just makes me leery.
—Trip Advice
Re: Make your plans and let her be mad.
Also, this is a situation where LW overheard something that wasn't intended for them. It's entirely possible that LW's brother told FI she was being out of line.
If no one has said anything to LW, there's no need to make waves.
If so, there's no point in engaging anyway.