This cat NEEDS to see a vet! These are very dire symptoms and it would be impossible for anyone here to give advice other than to say this poor kitty needs medical attention ASAP. Where does your mom live? There are agencies that can provide financial assistance to low-income pet owners. Failing that, are there any family members or friends that can loan her some money?
"To close your eyes will not ease another's pain." ~ Chinese Proverb
“We must not refuse to see with our eyes what they must endure with their bodies.” ~ Gretchen Wyler