The inattention and slow processing could be to blame. Both could cause her to wait too long to go to the bathroom.
Also, struggling with transitions can do the same. If she’s doing something, she has to stop, transition to going to the bathroom, finish that, then transition again back to what she was doing. While this is natural to most of us, it’s quite a process for a brain that struggles with executive functioning.
If it’s due to inattention or executive functioning deficits, ADHD medication could help.
You’ve probably done this already, but, if not, read about enuresis.
As you stated, punishments aren’t working so there’s no sense in continuing to try that. It’s also a signal that the wetting isn’t intentional or a lack of caring about it happening. If it was, punishments would likely correct the behavior.
ADDitude Community Moderator, Parenting ADHD Trainer & Author, Mom to teen w/ ADHD, LDs, and autism