regarding the gagging, it's quite normal for lo's to gag while they are getting used to solids. not choking obviously, but making that soundless 'o' shape with their mouth and gagging is not uncommon, it actually helps them learn how to do it.
i am not sure about the vomiting - is it happening every time? just with certain foods?
can you try giving her very small finger foods? what worked really well for us were slightly mushed peas or beans, cheerios, very small steamed pieces of veggies and small pieces of fruit, and rice cakes. also i would take thin slices of cheese and cold cuts and roll them up for him to hold and bite. also i would take sandwiches and then much the bread between my fingers so it would flatten and break off small pieces for him till he got used to bread.
for the record, my ds never ate the chunky mixed jar foods, he would pretty much spit them out and react badly. single foods always worked better.