Welcome to Healthcare Magic forum.
I understand your concern and appreciate your efforts for providing first aid to your friend.
She has suffered a blunt injury to the head which as of now doesn't seem to be much worrisome.
The bump indicates soft tissue injury
and swelling which can pain for a couple of days more .
The dizziness might have been due to the sudden impact and resultant postural hypotension
.That she did not have any loss of consciousness
, vomiting, convulsion external bleeding are all signs that make the possibility of internal brain injury
However she should be watched for development of any new symptoms like headache, blurred vision
, nausea, persistent dizziness
, any involuntary seizures etc for another 24 hours.If there is any such symptom she should seek emergency medical consultation for a clinical evaluation and CT(computed tomography)Scan brain if needed. Otherwise the injury is likely to resolve within a week with supportive management like antiinflammatory analgesics (acetaminophen
, ibuprofen etc) for pain and swelling.
Local application of ice was an apropriate first aid and can be repeated for soothing relief however after 24 hours it's not advisable since healing requires adequate blood supply which may be decreased by such measure.
Hope I have answered your query.
Wishing you good health