Thanks, Kirsty; I will keep trying that line of research. Interesting that Henry Smith's sometime-employer's eldest son and heir was born in September 1847 (do you know where?), around the same time that my great grandmother was born in Paris, France. I suppose, though, that even if Julia (the Marchioness) stayed home for the birth, her husband may possibly have been abroad with some staff .....
Any further information you have about the family's whereabouts in the mid-century decades, or how to find it, would be welcome. Do you have any idea why they were in Reigate, Surrey, at The Priory, in 1851? Was Culzean Castle being renovated for them at this time, perhaps? In addition to the normal domestic servants, they had 4 "grooms" at the Priory, as well as Henry who was not living in but very close, so it seems to have been an equestrian concern of some kind.
Thanks again,
Anne