Hi Snowkitty and welcome! Sorry to hear that Portia is going to need to have some teeth pulled. I don't think that I would have much luck with my 4 brushing their teeth, but I know that there are many different types of materials on the market. One I know of I believe just fits over your finger and if you can just get that into her mouth and gently rub I would think that would be the best way. I know they have special kitty toothbrushes and that you must use a special kitty toothpaste as human toothpastes are not good for them. As for only feeding her soft food, I would think that a certain amount of dry food would be good for her. Our 4 kids have gum problems and we have been told to give them Friskies Dental Diet as it helps to keep the tartar under control. I also give them Clindamycin treatments every 3 to 4 months.