
Would not be concerned about it being undigested that was why it caused a chuck-up, the dogs system was busy coping with other matters and was not in the mood to digest food. It is natural for a dog to carry undigested food in the stomach because in the wild they would hunt, eat, rest and then return to the packs young and regurgitate for the young so it is a normal function of a dogs stomach to act as a shopping bag.
Just give her a couple of easy days with extra small feeds and see how it goes, of course, if you become really worried about her then see a vet.