"Who has Sofia's underwear?"

I knew my cousins would have some good quotes! So we're getting ready to leave Grandma's 90th birthday party, we're all packing up and I hear this question being asked by a cousin to her niece. First of all, who is this Sofia? We have no one in our family with this name, which makes the question even odder because now we have to go looking for some stranger's underwear. And secondly, why would my cousin be asking a 5 year old this? Thankfully Sofia is a doll and the underwear was quickly found, but it was still pretty funny. Although not as funny as if it had been grandma's missing drawers....