Maybe try sitting down when you are both calm and saying that you are worried/concerned about her as you are trying to do the best you can and you feel it isn't good enough and take it from there.......its difficult but try not to get emotionally charged or drawn into the 'you do' 'I do' conversation regarding the house work and what you are paying for.

If you try and work at it from the angle of caring for her and concern then I am sure she will see that you are trying to help.......sending a big hug for support x