Asking for MIL to take my daughters presents back.

MIL brought my daughter a massive rocking horse for Christmas. We live in a small house so there is no room for it. We also have a rocking horse that's been living in our living room that we got off Facebook for free 6 months ago. My daughter never plays with it and I have been thinking about putting it back on Facebook to give to someone else. MIL would have seen it out. She never asked if she could get it her. It's too big for our house and I was so pissed off when I saw it get opened. We literally don't have the room for it. We were gonna ask her in the new year to send it back but I want to get rid of it now as the box is just now lying around in our house. I just know I am going to get the blame for not wanting it even though my husband was annoyed when he saw it too.