Fix the teeth. Not chewing sucks. Tooth pain sucks. Do what you have to and spread it out. You can get major dental work done outside the US for a lot less. Like, half or less.
Edit to add: saltwater rinse 2x a day.
Boil a pot of water and dissolve as much salt as it will take. Turn off stove and let cool on burner.
Pour out to cup and keep it covered with Press-n-Seal.
Gargle morning and before bed after flossing and before brushing.
It will stave off further decay until you can get her the care needed.