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.
If your parents pay your medical bills -- again, paying the money directly to the hospital or doctor, not to you -- that's tax-free and cap-free too. When your mom gives you more than $13,000 one year, she can choose to pay gift tax, or she can choose to use something known as the unified credit instead.