Thank you for your query.
You have neither mentioned the age of your daughter nor the duration of the swelling.
If the swelling is not increasing in size and is not painful then you should not worry about it. Even if it is just a sprain
the ideal thing would be to strap it with the adjoining finger so that movement is restricted and the knuckle gets rest. Wait for another 2-3 days and if the swelling does not subside then an x-ray may be required.
I hope I have answered your query to your satisfaction.
Wishing your daughter an early recovery.
Rajiv K Khandelwal