It wouldn't bother me. TBH, I'm surprised she actually remembered which outfits she gave. I even think asking for them back is a bit rude.... As for the tags discussion, with DD1 I removed all tags and washed almost immediately. Lots of stuff never got used due to ending up being the wrong season. With DD2 I'm taking off tags and washing as needed. If it looks like some stuff won't get worn due to being the wrong season they may just get left on the shelf with tags....
Totally agree. I've bought so many baby clothes for friends I honestly could not remember what I gave who. I don't think it would bother me to see a friend sell unused baby clothes that I'd given as a gift. For argument's sakes, with my 3 boys I have tons and tons and tons of baby boy clothes. And DS3 grew so big, so quickly there were 000s and 00s we were given that he didn't get a chance to wear due to the season and the fact that I had so many clothes to choose from, by the time I got to a few of the new ones, he's already outgrown them. Oops!