Given her signs, we have two possible triggers here. We can see salivating/swallowing with GI upset (from gut infections, pancreatitis, dietary indiscretion, etc) or oral irritation (eg if they ingest/lick something irritating, have a foreign body stuck in the roof of their mouth/between teeth/under the tongue or have oral changes (eg ulcers, bad teeth, trauma, etc). Less often it can be associated with salivary gland inflammation/infection.
With this all in mind, we are limited with what can be done at home. If you are able to, try checking her mouth in all those sites for anything stuck that you could possible remove. Be careful of course. And if you did find something stuck that couldn't be gently taken out, then she should be seen. For gut upset you can try an OTC pet safe antacid [ie Pepcid (0.25-0.5 mg per pound every 12-24 hours),Omeprazole (0.25-0.5 mg per pound every 24 hours), Tagamet (3-5 mg per pound every 8-12hrs)]. Whichever you choose, we’d give this 20 minutes before food to allow absorption. Though do double check with your vet if she has a known health issues or is on any medications you haven't mentioned. Afterwards, let's try giving small meals of a light diet (eg rice with scrambled egg, cottage cheese, boiled chicken, boiled white fish, or meat baby food (as long as its garlic/onion free)). And if we cover these bases and she settles, we are happy. Though if she is very sore in her mouth or this persists, then we'd want her checked for those other issues and potentially have antibiotics started.
Afterwards, please take a moment & rate me with the **STARS** (or leave a written rating of 1-5; 5 being great). Otherwise the site won't credit me for helping you. There is no extra charge for this & rating me now does not close your question. We can continue until you are satisfied, simply use the reply box and let me know. Thank you! : ) **