I have kept some of my son's baby clothes and if either of my sons has a baby, I fully intend to lend these clothes to my daughter in law. They will be clean and in good condition. Even now, I am looking forward to doing this.
I will expect my DIL to say a polite thank you, and will be waiting to see my grandson in some of them (sometimes). It will be a small but signficant milestone in our relationship. On the surface, I will be saying 'I hope you can find a use for these things' but underneath, I will be hoping to see genuine gratitude and a strengthing bond between me and the mother of my grandchild.
If she phones to tell me she doesn't want the clothes and is giving them to a charity shop, however polite she is, I will be very hurt. My son's clothes not good enough for her! Negating my treasured memories of being a mother! If she asks me if I want them back, I will feel a little better as it least she is respecting the fact that the clothes mean something to me.
When I visit, I will be hoping to see my grandchild in the clothes at least once.
If this does not happen, I will assume she has got rid of the clothes on the sly. So I will ask her in a roundabout way. And if I can tell she is lying or at that point she chooses to tell me she has disposed of them, she will go down in my estimation for being both insensitive and underhand.
So what if the clothes I give her are out of fashion? What is fashion to a baby! I hasten to add, I have only kept select things and would expect my DIL to pick and choose just a few pieces from the small bundle I will give her.
I deal in vintage clothes and am used to dressing in second hand things and so are my children, so perhaps I have a different slant on wearing second hand stuff. I still expect to be dealing in vintage clothing when I am a grandmother, so if my DIL rejects the idea a gift of baby clothing simply because it is second hand, it will not go down well at all!