John Charles was b London c1809 and was a retired colonel in the East India service. Mary Ann was born in the East Indies, as were some of their older children, so I assume they married out there
1851 - 13, Park Place, Chelsea
Samuel Haslock 73 - b Hulliwell, Northamptonshire. Retired silversmith
Caroline Haslock 30 - daughter, b London
Letitia Stoodley 21 - servant
[only question - would a silversmith's son become a colonel?]
If this is the one, a possible baptism (with the caveat there is a 1799 burial of a person this name in this location - no age given)
Samuel Haslock
Baptism 6 Mar 1778, Guilsborough, Northamptonshire
Father: John Haslock
Mother: Ann Haslock