My mother moved in with us a year ago after her dementia made it impossible for her to manage alone. She is very happy here and we have nothing but support from siblings. She has no assets other than life insurance. She has SSI and annuity benefit from my Dad's retirement and hopefully soon VA Aid & Attendance. We have to use a good portion her money for her care, expenses, etc. plus a share of household expenses. Do we have to claim that as income?
And congratulations on coming from a supportive family. Mom must have done something right in raising you all!
But what I would urge you to do is make absolutely sure that your mother's money is kept hermetically sealed off from yours. Her own bank account, and careful records of her expenses and her share of the household budget - a pro rata proportion of the utilities, local taxes, etc. It's fine to spend her money on her, but for peace of mind keep track of every cent.