If I were you, I think I'd be packing my shit and moving on, but you're the best judge of doing what's in your best interests. If you decide to try to make it work, sit down together and make up a list of household chores, splitting them between the two of you, say for example, you do the yardwork and she does the dishes, etc.
Just as you wouldn't throw down a piece of trash in your yard knowing it will be your responsibility to pick it up later, she'll be hesitant to make a mess she knows she's going to have to clean up later.
Put it in writing and stick it on the refrigerator with a magnet. Make it clear that these are the household rules, but they're subject to change based upon mutual agreement.
It might be slow going at first, and perhaps she'll never change, but it might be worth a try. Every family needs a set of rules, for both adults and kids. If the adults can't stick to the rules, then they're setting a bad example for their kids, and it's a good thing you don't have kids or your situation would be alot worse.
Her having a bad childhood is no excuse. Everyone has to grow up sometime and it's about time for her to grow up and be an adult now.