this is good that your neice had no episodes of unconscioussness , vomitting or bleeding from nose/ears. this indicates that there was no serious injury. the swelling on her head is due to the soft tissue injury
of the scalp
. Pain can be relieved by applying some ice on it and by giving some pain killer. You have already given her paracetamol
which will decrease the pain. it will take few days for the swelling and the pain to go.
thanks and take care.