I think you should wait a little longer until she goes to the bathroom without you taking her, my little sister is 4 going on 5 and she knows how to go to the bathroom by herself and my mom still puts a diaper on her at night and sometimes she doesn't. Its like a little test to see if she would be able to sleep without it she is just waiting a little bit more until she can get used to it but since your little girl is just stating just wait a bit more until you feel like she can go to sleep without a diaper