I have gone through that same situation on more than one occasion. You have to start with small amounts of clear liquids as little as an ounce. Give the liquid slowly and have a bucket or the bathroom handy just in case. If she keeps it down wait at least 20 minutes and then offer more liquids in small amounts. As she continues to keep the liquids down you can offer jello, popsicles and broth and then add bland foods like toast without butter and other things that do not bother the stomach. Good luck.