Hi
William Smith Senior seems to have married Charlotte Hart at Knebworth 20.7.1821 .
Both single otp .wit Thomas Briggs and Elizabeth Lumbris.
With the consent of parents.
He made x and she signed.
Son James bapt 16.12.1821 William and Charlotte lab Knebworth.
Given Charlotte was born in Edmonton ,the location of their marriage has to be something to do with him.
ps checking out the nephew George born c 1829 Edmonton ,it looks like parents Joseph Smith and Martha Sampson. Joseph given born c 1800 middlesex on 1841 census.
If so Joseph bapt 7.2.1802 Knebworth s of Jeffrey and Elizabeth Smith.
No sign of other children
Sorry just reread your original post ,quite a coincidence 2 William smith /Charlotte Hart marriages but the brother is still right.
Ciderdrinker