Ok,, well,, I went thru med school and was married to a physician for 11 years.. so here you go..
Never do anything to a burn but put cold water on it.. then leave it open as long as you can.. it is important to let the heat out! Once it has started to heal a bit you can use some antibiotic cream or aloe and a bandage.. loosely
For any type of food poisoning.. it is important to keep hydrated as much as possible
Then once you feel a little like eating again,, start out w/what is called the BRAT diet
bland food,, hydrate, hydrate, hydrate,, and it is also good to re-colonize the bacteria in your intestinal tract,, cultured yogurt is a great way to do this..
Water,, and Gatoraide type products are a good way to hydrate also..
If she simply can't keep anything down at all. then you may consider getting a PX for phenergen,, suposotory form.. they will knock her out and stop the vomiting..