PLEASE HELP!!!! We need some food mixtures for my cat...?

My cat is 16 years old and she has been showing that her life will be coming to an end soon. She's losing her hair, her sight, weight and just about everything else. She's been in our family her whole life and knows we care about her very much. Today, I fed her some wet cat food and it went right through her (if you know what I mean) so we need some ideas of food mixtures. I've heard that white rice and broth is good sometimes.. Please help, my parents are sad because of this..