She doesn't go much during the day, but she can't hold it long. She is not on any meds. As far as neurological or diabetes I don't know she refuses to go to the Dr.
She is overweight. She weighs about 240 and is 5'4-5'5.
Usually, 18 year olds should not be needing to void during sleep at night. This could be a problem with nighttime urine production, possibly related to timing of fluid intake or emptying. Look at fluid intake habits. Make sure she empties before going to bed, also make sure she is voiding regularly multiple times during the daytime. Is she on any sleep medications, such that she is not noticing the urge to get up and void? Are there any neurological issues, or possibly diabetes that need to be looked at?