Walked in on!

His little sister just walked in on us having sex. We were on the floor because his bed squeaks too much so we were on some blankets but didnt take much off. She slams the door open and turns on the light we all awkwardly look at eachother and she turns the light off and leaves.. We couldnt help but laugh, but she seemed upset afterward shes only 7 do i or we say something?????