My 6 Month Old Poodle/yorkie/?? Mix Has Been Throwing Up

My 6 month old poodle/yorkie/?? mix has been throwing up dark yellow foamy bile... 3 times in the last 9 hours. She ate 7 hrs. ago and her stools look the same. She is somewhat less active today. She has had all her shots with regular Vet visits and is scheduled to be spayed next month.