I think this is a pretty normal thing if this was the situation: After she ate, she ran around; thus, upsetting her stomach, which led to her getting sick. I honestly think a lot of dogs--as nasty as it is--eat their vomit after it has been thrown up. She's not going to die from eating her throw up, but just be careful and make sure that after she eats, that she has at least thirty minutes for it to settle before she starts running around and playing.
I have a 4 yr old female Boxer, and she always gets sick after eating if she rough-houses shortly afterward.
Hope this helped!
Just some observations