Maybe have her start out with a small goal, like one feeding a day she will try a cream soup or one of the carnation vhc drinks.
That is what I did in order to retrain myself on how to swallow. I was afraid to swallow anything at first. It took me a while to get those swallowing muscles working again.

I also rinsed my mouth out a lot with the baking soda/salt water solution to break down the mucous. I mixed a table spoon if each in one quart of water, which lasted me about a day.