Lay play, just bring up the race card on the racing post website and then if you have the full card in front of you you can just tap on the sire. The sire's record will then come up and it should be immediately obvious from his best runners as to whether he is a N.H sire or a flat one. In terms of e dam, well I don't think a flat mare will have visited a NH sire anyway. A bit simplistic perhaps but it'll get you 95% of what you need.
Lay play, just bring up the race card on the racing post website and then if you have the full card in front of you you can just tap on the sire. The sire's record will then come up and it should be immediately obvious from his best runners as to whe