I'm sorry, I don't know of anyone. However, Bismarck has an online classified ads site that you might try. I did a quick search there for both 'maid' and 'housekeeper' and found Sunny Maids, Green Maid, and the Happy Housekeeper along with lots of help wanted ads for housekeepers. You could try placing a free 'housekeeper wanted' ad.
BisManOnline - Free Classifieds
I looked in the yellow pages under 'home health services' and found several ads, including Spectrum Home care (homemaker, meal prep) (701) 355-0603 and Visiting Angels - nonmedical living assistance - meal preparation, errands, shopping (701) 250-1800.
Good luck. I know how difficult helping a relative in a distant state can be.