My 19mnt old, mouth sore, swollen lips???

My daughter has been snotty for about a week but no thee symptoms until yesterday. She started not wanting to eat and I examined her mouth where I seen a large sore on one side of her tongue. She has barely slept and this morning her lips are swollen. I'm calling the dr as soon as they open but was wondering what it could possibly be??? Does this sound like thrush or something viral???