I'm not quite sure how to handle this in a way that is fair to everyone.
Last year, my BFF, who is retired, moved to Costa Rica. She gave away or sold everything she owned that couldn't be put in suitcases. There was a lot of blithe "I'l never need this again!" going on, in all the excitement.

Some of the "give-aways" were leather jackets & pants, appliances, some furniture, lots of kitchen stuff (and some stuff, like tools and family heirlooms were "store these until or if I come back").

Some things, I bought outright, at almost dirt-cheap prices ($300 lamp for $50, etc.)

Well, she's sick of Costa Rica and is moving back in January. To an empty house. She hasn't said anything yet, but I'm not sure if I should offer her the stuff she gave me back (if I still have it-some things, I've passed on to other people), wait for her to ask...and it feels weird to tell her she needs to buy her own stuff back. I don't want to torpedo a 20 year friendship.

Any thoughts on the right thing to do here?

cm