OK. I think it's appallingly rude to give someone something, be it brand new or used, and expect to have any control over the gift afterwards - to expect them to return it, donate it, sell it (and maybe even give you half the money or what?), ask you if you have any use for it, or even just use it. Unless you specifically say something like, "Here, have this bag of baby clothes that my kid has grown out of, but I'd like to have them back when you've finished with them because blah blah blah" or "Have these - please donate them once you no longer have any use for them" or "Here's x amount of money's worth of stuff as a present, but I expect you to check with me before you get rid of it in whatever way to make sure I approve", you really shouldn't expect to have any control over it.
I really don't see why it would make a difference if stuff was brand new or second hand, if she's used it or not. Surely it's up to the current owner if they want to dress their kid in something they were given? If they want to use the oresent or not?
If you give someone a subscription to a magazine, do you expect them to carry on subscribing to it and read it cover to cover even if they don't like it, to ask you if you would like old copies before they chuck/recycle/donate/sell/burn them, or to keep them forever?