Surname Sheppard/Shepherd

Hello,

Hoping someone can help me as I am terribly stuck.

My GGGG grandparent were Charles Sheppard and Elizabeth Mary Grubb.

The only ones I have been able to find is a Charles and Elizabeth Mary that married in East Wickham 28 May 1826.  I don't know his parents, her's to my knowledge is a James Grubb and a Sarah Charnock.

My problem is the first born son was born in Bethnal Green, 24 Oct. 1822, why would they marry 4 years after his birth?  Plus this would have made Elizabeth Mary only about 14 years old.  Just doesn't sound right to me.

But, I can't seem to find another Charles and Elizabeth Mary's marriage announcement.

Can anyone help or steer me in the right direction?  Any help would be greatly appreciated.

Thank you so much.

Janey