I am so sorry your baby is so ill . This is always the most difficult decision a pet owner faces.
I would not want her last memory to be something she hates. Do you have a mobile vet that could come over?
I know you want her to pass at home but she may linger for days so you should make her as comfortable as possible by offering her tuna water or milk to drink.
Cats are attracted to smelly foods - the stronger the better. If she wants tuna, give it to her You can also try fancy feast, clam juice or baby food.
human baby food in meat flavours (check that there are no onions or garlic in the ingredients) and mix that with warm water and offer that, or syringe it in little bits into your cat's mouth. Beech Nut makes a line of baby food that has nothing but meat (beef, chicken, turkey or veal) in it. Here's a link: http://www.beechnut.com/Our%20Baby%20Food/Results.asp If you cannot find this, you could find another meat baby food - just read the label carefully to be sure there are no onions, onion powder, garlic, or garlic powder in it.
If her tummy needs a rest, feed baby food with no onion or garlic for a few days.
If she wont eat, and your cat is not diabetic begin by giving her two droppers (cc size) of unflavored pedialyte every ten minutes for an hour. Next water down(plain water) canned cat food or baby food chicken or turkey with no onion or garlic and give only one dropper every ten minutes for another hour. Wait two hours and repeat both. When she feels hydrated she will lick up the gruel on her own.
Give her droppers of unflavored pedialyte a few times a day to make sure she stays hydrated.
Please let me know how she is doing. I will always be here for you.
Sincerest best wishes,