@thingersandfumbs OP, this is becoming ridiculous. Stop buck passing. It does not matter whose dad is whose, what you have asked, how many times sheets are changed. You ARE where you ARE.
Op, reading this, YOU have to get stuck in. YOUR daughter has been left to her own devices for too long and this is disgraceful. She is a
Young adult but would have been a child while this started brewing. She clearly is overwhelmed by this, PARENT her! You need to lead by example op and get in there and get stuck in. My eldest DC is 18 and I would never have allowed this to happen or allowed him to get in such a mess. I am my sons safety net while he navigates this world. Yes,cleaning is boring, yes, parenting is a thankless task, but it has to be done and time allocated.
Help YOUR daughter. I appreciate you are busy , we all are! Help her clear this and then be involved daily moving forward. Being a parent is a life long commitment and does not stop when your child is 18. She did not wake up on her b'day,with a whole new set of skills or understanding.
Lead by example. YOU are her mum, YOU are the leader. LEAD for god sake woman.
Get your rubber gloves out, get some Zoflora, grab some flash & some bin bags and get on with it. Show this industrious young lady ,that YOU brought into this world, how to care for her basic needs.
I'm sorry if my post is brutal but sometimes I cannot quite believe what I see in this world. It doesn't matter how many other kids you may or may not have, how many hours you work, how tired you are. These are the choices YOU made. These are the responsibilities YOU willingly accepted. Time to step up to the plate OP. YOU are allowing a child ,you have given birth to, to live in what can at best be described as health hazard squalor. Get it sorted, immediately. I would never expose my children to that.
Take charge, be a mum. Care for your offspring and put in the necessary effort required to raise another human being.
Accept responsibility Op on simple terms