Am I overreacting

My MIL and I don't always get along. It's not as bad as some of these MIL stories I hear but we butt heads. She wasn't around when my husband was growing up because of addiction and she regrets missing out on his entire life so sometimes it feels like she's trying to be his wife. We spent Valentine's Day together. His mom for some reason decided to tell him that her parents house is going to be officially sold back to the bank and Valentine's Day was the last day to get anything out of it. She's known this for weeks but waited until Valentine's Day. He was raised by his grandfather so he wanted to stop by and see his old room. We did that and he brought down this fabric that was black from dirt. Both me and my MIL asked what that was and he swore it was his blankie his grandfather made for him. I don't know how he could tell because it was black and dirty. Before I could say anything my MIL goes "All right then. I'LL wash it and see." So his mom took it to wash it and sent him a picture saying "Oh you were right!" She's going to bring it back to him tomorrow m. Maybe I'm oversensitive but I could have washed it. Idk why he didn't stop his mom and say he would wash it or that I could. It was emotional for him to be there and I don't want to make it about me. Just annoyed I guess. I would have washed it. I'm his wife though his mom acts like she is