Thanks Geoff,
This marriage looks good. Geographically the village, township (or whatever it was) of Messingham is between Holme and Burringham.
I had already found these three siblings on IGI and the other two, Martha and Rebecca also on IGI C034881 baptised on the same day. Their ages on later census records look similar, maybe they were twins.
Curious point Althorpe is on the west bank of the Trent, directly opposite Burringham. I suppose it would not be unreasonable for boats to ply back and forth, whereas nowadays people just drive round.
Anyway, next step must try to find Robert Wilkinson's birth.
Regards
Martin