Sorry, Bev, I should have made that clearer - yes, this is in Hemel Hempstead. The Hookers lived here in Piccotts End, which is just on the fringes of Hemel nowadays, but was more of a separate hamlet in earlier times. They were a farming family with a fairly respectable amount of land - 85 acres, which I presume would be leased in some way from the local landowners. David Hooker (head of the household in the 1851 census) was born in nearby Great Gaddesden in c. 1810. He was widowed by that point but the same family appears in 1841 with a Catherine Hooker as his spouse.
I've quickly checked FamilySearch.org which has a David Hooker born in May 1809 at Great Gaddesden, parents Zachariah Hooker and Lydia (Tomalin) Hooker. They have him as one of 11 siblings.
Also according to FamilySearch, a 'Zacharias' Hooker, presumably the same one as the above, was born in 1776 in Caddington, Beds. I don't know whether you're familiar with this area but none of these places are very far apart.
It seems likely that these are members of the same family, but I'm not sure how they fit together. Might give you some food for thought, though.