Just be there for her. Help her around the house whether it is with cleaning, or cooking. Just make it know that you are there to help and that she doesn't have to take on everything herself and you are there to help.

Could it be that she's putting to much stress on her self trying to accomplish more in one day than she knows she can do?
Micro-managing is a wonderful tool, if it is used correctly.
But I agree with italian, be there for her, be her support, do what you have to do to help her out when you can.

Italian is right about helping in the house - I had both my kids cooking tea(dinner) one night a week from start of high school...Dont know if your Mum would let you do that....I didnt mind what my kids made - it was their choice but I thought it was an important thing for them to take their share of chores and also learn some skills for when they left home...Another idea would be to write letters to your Mum and Dad telling them how you're feeling and worrying about your Mum - only you know whether this might be a good thing? You could offer your help in the letter/s. It is possible that your Dad doesnt realise how much your Mum is struggling - especially if he's struggling too...Good Luck. Love M x