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.
Some states do offer paid leave, along with more enlightened companies, including Google, which gives new parents 22 weeks plus $500 in cash to cover baby-related expenses. Yahoo CEO Marissa Mayer increased paid leave for moms from eight weeks to 16; the company also gives dads eight weeks off.