DD says my snoring keeps her up at night but DH and DS say they can’t hear me

Sounds like you're both annoyed at each other? Is there something else going on at the moment between you both? It sounds as if you dont completely believe her which is strange and also the way she is texting you through the night saying you're selfish for snoring. Sounds like some tension there.
I'd tell her to try some earplugs and put your phone on silent so her texts dont wake you.

Some people sleep lightly. Is there any reason you think she’d lie?

I don't know how you are so confused, and if I was your DD I'd feel very frustrated at you.

Your DD bedroom is directly above yours and she has wooden floors, it's not that confusing at all, is it.

Stop playing the confused victim card and help find a solution.

Everyone needs to calm down. Sounds like the sound insulation between the floors is bad so it’s not surprising that the person in the room above you is the most affected. But that’s no need for name calling.

Can you work out the most effective room allocation to isolate the snorers from the light sleepers?

If you are waking up several times a night you could have sleep apnoea.

Please go and see your GP.
DH uses a CPAP machine for it and my sleep quality has improved no end.

You haven't answered the questions that people have asked about what you are doing to address your snoring and you don't seem to appreciate just how awful it is for those of us who have had to put up with it.

You think your DD is being selfish, but you are being just as selfish.

Well she’s 21, so if she can’t sleep because the people who pay the mortgage snore, she can move out. Or a cheaper option would be to get some decent ear plugs.

If she wakes you up.send her the listing's for flats in your area no conversation needed

It seems she’s getting at you for some reason, it all sounds like teenage behaviour on her part.
Phoning your mobile? I’d knock that on the head, no way would I put up with her purposely interrupting my sleep.
Yes it’s annoying if she can hear you both snoring but she needs to use earplugs and not be so awful to her own mum.
At 21 she should be having mature discussions, looking for solutions (sounds like she’s exaggerating anyway) and not calling you names.

As she’s an adult there seems to be a simple solution. When she’s in her own home she won’t be impacted. In the meantime your house, your snores.

Well there you go. The floors are probably less soundproof than the walls, so she can hear you snoring in the room below more clearly than someone snoring in a room next to her.

She will have to get some ear plugs I reckon not really much you can do.

Accept it- your snoring is keeping her awake. Do something about it. Change your sleeping position, get a carpet for her room, swop rooms with your husband. Sleep deprivation is horrendous.

This, surely the most obvious thing?

I’ve just asked DH as he is better with both science and construction. (🙂). He says that wood conducts sounds better then bricks so if you have wooden floorboards and brick walls sound will travel better from downstairs. Does she have a carpet in her room? If not sound will travel better.
It could be also timing issue - she is trying to sleep exactly when you snore but DH and DS snore later.

Of course it might be the just a blame shifting tactic on her side because you disapproved her sleep habits.

@ML5 oh OP, I have some ‘noise’ experience through work I must add lol

unless DH’s room is opposite and not adjacent to DD’s she hears YOUR snoring. You said they are next to each other, but that’s not enough.

noise travels in a straight line :-) so either opposite or top or bottom.

i am also a light sleeper. My brain also keeps familiar sound, so if she hears you said every other day, even when you snore is short on other days, brain will trigger the memory so dd won’t always be accurate how long your snore is all the time. Yup, this memory is enough to keep her up most nights, if triggered even so slightly as her brain is exhausted by the past.

I'd be looking at every remedy for snoring so that no one is hearing you or your husband snore.

It's a difficult problem as of course you can't help what happens when you sleep. But to just dismiss the impact on other people who have to tolerate it is awful.

I have an alcohol dependant mum who couldn't give a damn how awful the snoring would be for anyone else subjected to the deafening sound.

If I lived with someone else and I snored, I'd try what I could to reduce it.

So both her parents snore and her sleep is being effected?? It doesn't sound like either of you have addressed the snoring and that you don't seem to believe her. I can hear my husband breathing in a different room with the doors closed and him using a cpap machine so yes, some people have very sensitive hearing and their sleep can be destroyed by unaddressed snoring. Get yourself and your husband to a doctor and find out why you snore and get some good quality ear plugs for your daughter.

It could be your DH as he could have different snores. My DH sometimes produces really high pitched snoring which is absolutely unbearable you might confuse it with female snoring. His other “low type sound” snore is not so bad.

How old your DD ? Could it be that she is going through exam revision or similar worries and struggles with sleep hence her noticing sounds more? I would look at this, plus screen time and caffeine intake.