I'm not about to say that you should sit back whilst your DSC are being horrors - but IME, 10 is the age at which 'gobbiness' starts in some boys DS1 I'm looking at you, and your DSD is going from being her Dad's 'baby' to being the 'middle child'.
So there could be an element of regression because of that - but equally, my own DD had issues with wetting, up until 9yo in the day and 12 and a half at night, and would come out of school wet. She would tell me that she just couldn't be bothered, that she was too busy playing, etc.
It wasn't until years later, that she was able to articulate to me that she had been saying that because she didn't want to have to admit that she had an issue there. And if she told me that she was 'too busy playing', then she would have chosen that, whereas if it was just 'happening', and she couldn't control it, then SHE wasn't the one making the decisions IYSWIM.
But you do need to bear in mind that she is, in her mind at least, 'losing' her place as her Dad's baby. Going back to wetting may be a sign that she is not doing so well emotionally with that.
There are far better ways to discipline a child without resorting to physical abuse, though. Sanctions of things that that DC (or DSC) likes to watch, have or do, for starters.