I can't decide whether to get annoyed about this or not really. I keep seeing things we handed down to SIL for sale on local Facebook groups, so it's not even like she's trying to do it on the sly. It is making me feel as though I probably won't give her any more stuff, I'll just take it to the charity shop (if they actually want it obvs) or donate to a local clothes bank etc. It's also making me grit my teeth a bit when she describes things as "barely worn" and I'm thinking, "er, I got that second hand and my kids wore the shit out of it". Mention it or let it go?