I’ve kept hold of a could of bags of clothes from when dd was little. The rest I free-cycled, gave to charity or sold on eBay. The only people I had to give to was my brother and his wife. They consistently treated us - especially me - abysmally. So no way would I have wanted to pass things onto them.
As is, they have a ds. I was mightily glad of this as sil would have been all over the clothes like a rash despite having screamed at me, my brother physically threatening me and physically hurting me, their dog biting my dd on the face as a baby etc.
I know that the decision not to give toys was met with disapproval from sil and my mother. But I don’t care. I didn’t want my dds things in their house. I just couldn’t stand it. My brother was spoiled and given everything as a child including power over me, which has made him a hideous adult. His presence made my childhood very difficult and the bullying continues into mature adulthood. I didn’t want him to take anything away from my parenthood. We are finally NC with them.
I would love to have a loving sisterhood relationship where we swap between eachother, treat eachothers children with care and respect. But I don’t have that. And it is really sad. The last time we saw sil was the day of my stepdads funeral (so dds grandpa) and sil screamed at my dd (8 at the time), called he manipulative because she was upset and crying over a toy.
We don’t know the back story and the history behind why you dont want to share. But no, you should not be forced. In you shoes, I would pretend you are also ttc and want to keep the clothes nice for your next baby. It may cause ructions, but it is your choice and your children’s clothes to give away when you are ready.