V.T.
I know exactly what you are going through... I lived it a few years ago with my ex- mother in law.
In her eyes, its not that you are doing everything wrong its that she is use to doing everything herself so she will keep doing it herself. You are dammed if you do... dammed if you don't. What I did was I stopped doing everything and let her crazy self do it all. I felt really bad, but I was so tiered of her making me feel useless. Then I had time to consentrate on the important things like taking care of my baby.
I think you should aternate, clean up every few days and let her worry about the rest. Either way she is going to go back and do over. Don't let this get to you, you will end up disliking her. She is old and will not change her ways.