This is the same as us.
I've got a DD and DS, both aged 13 and both have SEN so it's a bit different I guess.
DS doesn't care about nudity at all, and runs around most of the time wearing a nappy and nothing else.
DD covers up in front of her dad, but not in front of me. I regularly offer to give her privacy but she's not fussed. She does close the door if she's using the toilet (thank god haha!), but that's it. Although she doesn't get changed in front of her dad now, she doesn't care about her dad getting naked. He quite often strips off downstairs - because that's where the laundry basket is - before going upstairs and having a shower.
Both DD and DS still need me in the bathroom to help them with showering/washing. DS needs more actual physical assistance, DD just gets anxious and needs help with washing her hair (sensory issues).
Neither DD nor DS seem to feel the need to give me any privacy and quite happily barge in if I'm in the shower, or having a wee. In fairness, I'm extremely open about my body and have made a real effort to promote body confidence. I am really overweight and need to lose a few stone, but I never talk about being fat or hating wobbly bits - I talk about needing to get fitter and being healthy.
I think it's healthy to be comfortable with nudity - naturists lead a totally nude lifestyle with both sexes mixing and there's nothing salacious about it. While I'm definitely not a naturist, I think there's a lot to be said for not making a big deal about nudity. I come from a very private and closed-off family while DP's family all undress in front of each other, talk to each other in the bath etc - it was quite mind-blowing when I first met him but I soon realised what a positive mindset it was. People in his family are all shapes and sizes but no one seems to have any real hang ups. I find it refreshing.
If either of the DC wanted more privacy, that would be absolutely fine and I regularly check in with them about this - usually when it's time for a shower/bath. But I think being comfortable with bodies is very much ingrained in our family habits so I don't anticipate any huge changes. Naked conversations are commonplace and tbh, no one even really notices!