Boil on her face doesn't lead to symptoms like pain when swallowing food.Most probably,she might have acquired with Throat infection/Upper respiratory tract
infection.As the breathing is uncomfortable,it might have spread to lungs/lower respiratory tract.
You didnt mention whether she is having cough
or not.If at all it is present,whether it is associated wit sputum?
Please consult your local doctor immediately as the acute condition which is present now may turn chronic and it may take long time to get cured.
All the best.