Working forwards is time consuming but not impossible.

You have Edward's marriage: look for children on the IGI through Familysearch.

Rent the films of the relevant parish registers and work through the births from a couple of years before the marriage for about 25 years or until their children stop appearing. Work through the marriages from about 20 years after the births of the children - though they might not all have survived, stayed in the same parish or married.

If you have access to Ancestry you can find Edward & his family in the census every 10 years - you already have 1851 - which will give you locations and an idea of surviving children, rough death dates for Edward & wife, if one appears as a widow/er, and much useful & interesting info. You can track the children in their separae households when they grow up.

You can look for their marriages/children in Brian Lawson's indexes for later years, as well as burials.

Wills - many also on line - can give not only the names of children but some of their family members too.

It takes time, but searching for IOM family is easier for non-local researchers than looking for English family - mainly on account of Brian's indexes (if the IOMFHS play fair).

These are just my top-of-my-head thoughts. A more expert researcher would give you a better idea. Good luck.