You shouldn't need to disclose it - without knowing the incident circumstances, it's going to be accepted that driving abroad is an increased risk as the controls for the vehicle ar eon the other side of the vehicle, and you would be driving on the other side of the road, so the potential for mishap is increased.
Equally, UK and USA database (assuming they exist over there at all as a national entity rather than state by state) are not shared.
Interestingly, we don't need to know about claims made on mopeds - don't know why, but I'm in fraud, not underwriting.
A claim wouldn't be affected if the insurer somehow found out about this accident, and they would only find out if you r daughter told them