Welcome to JustAnswer, this is Dr. Christie.
I would recommend having your vet out to look at her. There are a couple of things that could be going on with her.
Lumpy jaw, which causes firm swellings on the jaw and head. This is caused by a bacteria called Actinomyces bovis. The bacteria normally lives in the mouth and gains access into the tissues by small abrasions in the mouth. Treatment is using an iodide solution IV. If treatment is not done or is not successful, it causes the animal to waste away due to the pain in the mouth from chewing, etc.
Wooden tongue. You mentioned her tongue is swollen too. This is caused by a bacteria called Actinobacillus lingnerisi. This can cause swellings in the mouth, tongue, and head. Treatment is with a tetracycline or with iodide therapy.
Abscess from foreign body. Certainly cattle can get abrasions in their mouths. They can also get foreign bodies such as foxtails, thorns, etc in the mouth. This can definitely set off an abscess and cause either of the conditions above.
I would recommend your vet to check her out to determine which you are dealing with. I would start her on LA-200 until your vet can get out to see her. Unfortunately there is a chance that the treatment may not work if the disease is too far advanced.
LA 200, also called Liquamycin) is oxytetracycline. It is available at most feed stores, your vet, and some online pharmacies.