A quart is 2 pints. A pint is sixteen fluid ounces of water and weighs about 16 ounces (avoirdupois weight.) A gallon is 4 quarts (8 pints) and thus weighs about 8 pounds. Five gallons would be about 40 pounds.
In some cases, if your mother is on Medicaid, she can designate you as her personal home care aide and you can get paid a small amount through Medicaid. If your mother has her own resources, you can draw up a contract agreeing to work as her home health aide and she can pay you a salary that you both agree upon.
So, for example, if Mom was in the nursing home for two years and the state was paying the nursing home $4,000/month for her care, then the state will file a claim against Mom's estate in the amount of $4,000 x 24 months = $96,000.