Does the carpet become impure if a baby girl urinates on a sheet placed on the carpet?

If the bedding and carpet are dry, the impurity does not transfer from them to it. However, if one of them is wet or damp, impurity may transfer according to many scholars. If there is no certainty that the impure spot touched the pure one while one of them was wet or damp, then impurity is not judged to have transferred, because the certainty of purity is not removed by doubt.