Yes, - that is them.
Richard, the father, having pensioned out of the army in 1817/1818.
He died in 1843 and the wife Anne, Richard the son and Louisa moved to Hampshire. I didn't believe it to begin with and dismissed the census of 1851. But after finding Richard in Westminster as a private tutor (born in Cape of Good Hope)- I then found Louisa in Westminster getting married. (Well it was all just possible).
She has obviously played around with her age (even in the 1851 census); that is what threw me off originally.