Are the floor and carpets considered impure due to brothers entering the restroom with the same shoes they walk in the house with, and the carpets getting wet and walked upon?

The ground and carpets are not judged to be impure, even if damp, merely by being walked upon with sandals that are worn into the toilet, unless the impurity of those sandals is ascertained. The girl who walks on the carpet does not become impure by that. As for changing all clothes and avoiding carrying the child because of this, it is an exaggeration. Nevertheless, one should be cautious for prayer by avoiding clothes whose purity is not ascertained.