My 3.8yo has been wetting her pants. Sometimes is a full on pee, but mainly it's just wet pants and not wet enough to get her trousers iyswim.
Sometimes I think she does it because she doesn't want to stop what she's doing. It's been going on for a few months now. I've tried ignoring it and just changing her, encouraging her to use the toilet more. But it's really getting me frustrated now and I have been angry with her. She's been toilet trained since 2.
Perhaps take her to dr to rule out an infection (they don't always have pain with it). If clear, then you're probably right about her not wanting to stop what she's doing. DD was the same at a similar age (having been toilet trained since 2 yrs 3 months). Give lots of praise for dry pants (?sticker chart). Maybe set a timer for her to try every 30 mins or so when at home. We found that pointing out that cleaning up after an accident took her away from her activity for longer than if she'd just used the loo on time was the turning point. Take your time over it (quick shower or bath, change of clothes, get her to help put wet clothes in the wash etc.). She'll soon realise that a quick loo trip is preferable!