Your little daughter is suffering from a Pyoderma
and it is normal practice to give oral antibiotics
to cure it.
If it already is pus filled then the pus will either come out spontaneously or on will have to be removed by a small surgical procedure.
Most of the time if the boil is a small one it heals spontaneously with oral antibiotics only in very few cases one has to go through the surgical procedure if no response in 3-5 days