She doesn't have any siblings and very rarely does she have a nightmare maybe a total of 3 in her tiny little life. she has been doing this peeing her pants thing on and off since she was 3. She has months where she goes to the bathroom fine with no accidents and then boom she starts peeing. day and night. .. I have played investigator to figure out what has changed and as far as I have found nothing changes its kind of out in left field... we go back to potty trading every time using pull ups and not punishing just rewarding good habits and she just doesn't seem to care and then months of peeing her pants will go by and then she will just stop and use the potty normal for months and then go right back to peeing again. ..
There are many things that could be causing this behavior. It's time for you to play detective and figure it out. First things, go back to potty training. I gave my daughter candy every time she used the potty and put her on the potty every 30-40 minutes throughout the day. Some people use reward charts. Do what works for you.
Using the bathroom causes some children a lot of anxiety. My daughter would rather go in her pants than go in a port a potty or a loud, crowded bathroom. She likes to go alone with the lights off. I think she doesn't like the process and it makes her nervous, particularly at school. Just be patient and keep working with her. Don't give up.
If you do see blood in her urine demand some more tests from her doctor. If she holding it and sitting in her urine she is at high risk for a UTI.
The Q is there night mares or another child not potty broke yet some time they like to fit in even at a early age or not happy going to bathroom alone.