Thank you for your question. My name is***** I have been a small animal veterinarian for 13 years and I'd like to help with your question.
Like most things, what is going to happen depends on how much and how strong the tobacco was.... However, the nicotine in chewing tobacco can cause hypersalivation, vomiting, heart arrythmias, tremors, seizures, or weakness. First you see stimulation (agitation, tremors) then later on you see more of a weakness.
Since the ingestion was recent, it may be helpful to induce vomiting. Vomiting induction is most safely and reliably done with drugs at a veterinary clinic, but sometimes you can do it at home with hydrogen peroxide. There is some risk of aspiration if they get some of the vomit in their lungs when you induce vomiting so I would only recommend it if you understood that there is a risk.
She is probably 40 pounds or so so she can have a single dose of hydrogen perioxide... approximately 1 TBSP. If it works, great, if not then don't give more. It may also help to give some activated charcoal to absorb the nicotine in her gut. Ideally I would take her to a veterinarian for the vomiting induction and the charcoal, but if that isn't an option you can try to induce vomiting at home. Then monitor closely for the next 12-24 hours. If you see signs of agitation or weakness then she really needs to see a veterinarian for supportive care.