watching children

This afternoon I was watching my friends daughters they are 5 and 3 years old for few hours. They both working and nobody can watch their daughters so I said I can watch them after work. The girls likes to come over here in my house because they can get to play my children. They are both very good girls so no problem with me. She said that Friday again if it is okay with me and I said it is okay. My children likes to play other kids and I like it better when their friends come over here to our house and play than them come to their house. Here I can watch them and check of what their doing while when they are in the other house it makes me worried.