why would she have problems with bed wetting there and not at mom's house?
off the top of my head:
1) She's being given something to help(make) her sleep soundly and can't wake up to use the potty.
2) Stress. It is stressful in the home, lots of fighting and yelling or physical violence.
3) Someone is abusing her in some way.
4) Bad night time habits (drinking a lot before bed), left to fall asleep in front of tv with no bedtime routine (using potty and brushing teeth before being tucked in).
ok, complete and total speculation here but what if...
the house is chaotic, the children have no routine, Haleigh is missing school - run down & sick a lot because she doesn't have regular sleep schedule.
She's missed too much school and they have been put on notice, they've been turned in to child protective services, they had to move into a larger and probably more expensive place because of cps intervention regarding this situation. Misty & Dad decide they must get a routine going - Dad (or gf) decides to give otc meds to induce sleep at regular hour to get a schedule going.
Dad just started working nights, so administration of meds falls to GF, who by the way doesn't know if child weighs 40,50, or 60 lbs. She overdoses her. When she covers her with the sheet (the point at which she breaks down on camera in her story) is right after administering meds. JR gets lucky and gets the correct amount that time?? IDK
Later she notices haleigh is unresponsive, bedding wet from bodily fluids, or whatever... Dad maybe has a lunch hour or something to run home real fast. They decide if they call 911 JR is gone to CPS asap & so they fake abduction and he takes her with him when he leaves.
Now, certainly if she had died there, the cadaver dogs would be able to tell so maybe this needs tweaked to he rushes home to take her to ER - and she passes away in route or something.
just thinkin outloud.