Steve,
Did you mean you found a birth of a James Cogger in 1868, not 1968 as you typed?
I can't find one in 1868.
I do mean Edgar born birth Q1 - 1869.
References BMD - Q1 1869 Cranbrook and your LDS baptism in Apr 1869 with the correct mother.
James and Helen married on 21 Dec 1866 in Hawkhurst.
James died Q2 1867 (Maidstone district - he was a Policeman in East Malling when he married).
If Edgar was born in Q1 1869, that's a minimum of 15 months after James died.
In the 1871 census (2 April) Helen Clyde Cogger is a widow living with her widowed brother in law Edwin Caffyn (his wife, Helen's sister, Mary Ann died in Jan 1868), his and Mary Ann's son William Nelson Caffyn and Helen's son Edgar Cogger.
On 28 April 1871 this 'family' arrive in Quebec as passengers on the ship 'Pomana' as the Caffyn family.
We can find no record of a marriage between Helen and Edwin between 2 April and 28 April - unless maybe it was on the ship - they were both widow/widower?

Edwin we believe dies within days of arrival (though we haven't seen a proof record yet).
In the 1881 census in Ontario they are living with Henry Fletcher under the name Fletcher even though Helen Clyde Caffyn doesn't marry Henry in Toronto until Nov 1882. In the 1881 census Edgar is 12 (correct) and there is another son Edwin (9). Edwin must have been born 1871/2, so we guess he was born soon after arrival in Canada and was named after his father - maybe that is why the family emigrated as Helen getting pregnant by her dead sister's husband wouldn't have been accepted? We are fairly sure Edgar 'Caffyn' ends up in the USA - yet to be proven. We suspect Edgar b.1869 and Edwin b.1871/2 were both fathered by Edwin Caffyn, but again we don't have definite proof.
Intriguing.
Daz