Hello, my name is***** and I have over 20 years of experience as a veterinarian. I am sorry to hear that Gracie is vomiting and walking gingerly today.
I suspect her posture is related to a painful abdomen.
In many cases vomiting is triggered by eating something they should not, too much table food, too many treats or something they find outdoors.
More serious causes of vomiting include viral or bacterial infections, chronic pancreatitis, esophageal reflux, a dietary allergy or sensitivity, inflammatory bowel disease, internal organ failure (kidney or liver disease), a full or partial gastrointestinal obstruction or even infiltrative cancers such as lymphoma.
Because she is an older girl ideally she would see her veterinarian. I understand that may not be possible today because it is Sunday.
If you want to try something at home to see if you can settle her stomach you can give either:
1) Pepcid ac (famotidine) at a dose of ¼ of a 10mg tablet per 5 to 10 pounds of body weight every 12 hours
2) Prilosec (omeprazole) at a dose of ¼ of a 10mg tablet per 5 to 10 pounds of body weight every 24 hours
These are both acid reducers and either one should help her feel better. They are quite safe and can be used long term if necessary.
I would pick up all food for now and water for a couple hours to allow her stomach to settle after the acid reducers.
In a couple hours when you give her water make sure it is in small amounts only. If she drinks too much too quickly that can lead to vomiting. To get some electrolytes in you can also offer her a 50:50 mix of pedialyte and water.
If there is no vomiting for 12 hours offer a bland diet of 1/3 boiled minced white skinless chicken or boiled, lean hamburger, with all fats drained off the meat after cooking, and 2/3 boiled white rice mixed with some low salt chicken or beef broth to make it easy to lap up and swallow. If she refuses that you can offer a little meat baby food. If she refuses both then don't push it she needs to see a veterinarian.
But if things go well and she does eat and doesn't vomit feed her the bland diet for 2 to 3 days then slowly start to mix back in her regular food, a little more at each meal. It should take about 5 to 7 days to slowly convert her back to her regular diet.
If she continues to vomit even with the acid reducers, runs a fever (more than 103F rectally), has a tense painful belly or if she refuses to eat she should see a veterinarian for an examination, diagnostics, injectable anti-nausea drugs intravenous fluids and supportive care.
Please let me know if you have other details or a particular question based upon my response.