Can I write off my dependent care expenses if the person who was watching my child is over 19, not my dependent but was filed as some else's dependent?

My babysitter had a side job of watching my child and me paying. Not sure if this will mess up the person who claimed my babysitter as a dependent when they filed. Can dependents have side jobs? I paid over 5000 and would not want to lose it but also i do not want to raise any flags if she was not supposed to be working