Kibble or canned?
I would say your biggest problem is her diet. Change to a high quality, human grade meat and you will find a world of difference in your cat. Check the ingredients in the food you are feeding and ask yourself should a CARNIVORE be eating this?
Here is a great link:
http://www.catinfo.org/
My favourite food is Nature's Variety, Instinct canned,
Weruva, Wellness grain free, GO! are all good foods also.
Cholesterol in cats can be high after they eat and an accurate blood reading for it should be done after a fast.