Hi, my wife and i did stand up paddle board this morning before 12pm - she fell, hit her foot on the board but no pain until 4. throbbing now?

Possible fracture: This should be checked out. If there is "pin-point" pain of the area, there is the possibility of a foot fracture. The other option is to ice it for the first 24 hours, keep off the foot for a few days and see if the pain remains or if it resolves rather quickly. Overall, pain and swelling that remains in the local area should be checked out if it is still significant after 48 hours.