FYI,
If you do an ancestry.com search on the surname, input the parents names, restrict years to 1838 +/- 10 years, and restrict to Middlesex you will see many of the baptisms for the children of John and Elizabeth. Is it possible his first names were John Francis? If so there are children before Ann. In particular John Thomas Monks, born Feb 18, 1829 to John Francis and Elizabeth, at Holywell Lane, Shoreditch, father's profession is Weaver. Also Elizabeth Frances Monks born Mar 7, 1832, to John Francis and Elizabeth, at Holywell Lane, Shoreditch, father's profession is Weaver.
arky101