thanks for your query.
There is hematoma
formation over scalp which is due to rupture of small blood vessels.it will take few days to subside.
Apply cold compresses over injury site.
as per dosage for pain relief.
Observe signs of head injury
Any abnormal activity.lethargy..vomiting
.bleeding from ear or nose and in case you find any get htake her to ER.
Wishing your baby good health