Does she get to have alone time with her dad? Has he ever offered to take her out anywhere, a nice meal and a chat, day out to a theme park? Bowling?
My husband always took my step-daughter out when she visited, even if it was just a trip to McDonalds, (depending on finances obviously) where he could catch up with what she'd been up to, since he last saw her. He would enquire about her schooling, her friends, how she felt - just generally showing her that he cared for her and loved her just the same as before, and just because he was now with me, didn't mean that she was going to be suddenly abandoned. I think any child is just looking for that reassurance and love, and in my case, I was seen as a threat to my step-daughter, someone who was going to take her father away, or stop him from loving her. (this is what she told me at a later date, when we became great friends).
It may not work for everyone, but I found the best approach was to take a step back and let them have lots of one to one time where she could open up to him and voice her worries or fears without my interference, until she realised that I wasn't her enemy, and I wasn't a threat. A softly softly approach and lots of patience eventually brought us close together and we became great friends.
She was 14 when I met my husband, and she is now 38. We have a great bond and I treat her no different to my other 3 children, who are also very close to her.
You say your husband has talked to his daughter many times, but it all falls on deaf ears. Is he talking at her or to her? Is he having a friendly chat or is he just moaning about the mess? I think the mess is the least of your worries, I think his daughter needs validation and alone time with her dad, and maybe she will eventually open up to him about why she behaves the way she does. Obviously she isn't going to want to have these chats with you in the room, because at this stage you are probably seen as the enemy, like I was.
I mean, what is there for her to look forward to when she visits? She obviously sits in her room because she is fed up and probably does't want to be there. (I don't mean that to sound harsh btw).
If what you are doing now is not working, then you need to change tact. Sometimes, nothing we do will help, but she is young and may warm to you as she gets older. Unfortunately there are no guarantees, but at least you can say you tried.
Apologies for the long post - good luck going forward.