It is very nice that she is will wash her own sheets however thats not protecting the bed mattress from urine! so she needs to understand that having a sheet on the bed will protect the bed also I agree with you that the nappies route has to be her decition and not yours she is 15 and to be honest wearing a nappy isnt the answer especially when it is not a consistent thing since birth!.although on the other side of the coin she would wake up in a dry bed!that is the pro's and cons of the matter!.but its up to the individual to decide has she mentioned wearing protection to bed or no? mind you it is not something that would spring to mind! for a teenager when i was young I wet up till age 17 then it stopped !best wishes, Tom (Parent to three children