My grandmother gave away my clothes without telling me

**I have nothing against giving clothes to charity. It's something I regularly do myself...Just saying this as I don't want it to be read in the wrong way**

My grandmother took me to the PDSA charity shop in my town earlier today and she pointed out that my old bike was at the front of the shop. I had no problem with that. I haven't used it in years and I would've willingly given it myself if I had known I still had it (I thought my grandparents had given it away years ago). However, when we walked in the shop half of my wardrobe was in there!! She had no problem in jokingly pointing out all of the things she had given away without me knowing a thing. If she had asked me, of course, I would've given some of those things away. It's raising money for a very good cause. In fact, she had asked me the week before to give her some clothes to go to charity and I gave her quite a few. I just have a problem that she went through my stuff and gave away my clothes and I knew nothing about it and she doesn't see anything wrong with it!

Am I being unreasonable?