Hi,
Think I've found your Charles Cove.
Mary Ann Durrant was NOT a widow when she married Charles Cove Snr (I can only assume she thought she was or had run away for whatever reason)
Mary's first husband was John Smith Durrant and they married in 1824 in Watton, Norfolk.
They had three children William Smith Durrant (also on the 1841 census with Mary Ann Cove), Harriott Smith Durrant and James Smith Durrant - Smith is a middle name running right through the family.
At some point Mary found herself in Hackney and getting married to Charles Cove in 1840. On the marriage cert it says she is a widow. I have yet to find where John Smith Durrant was at that time. William must have gone with her but Harriott remained in Norfolk. James I think died young.
After Charles Cove Snr died, Mary and the kids found their way back to John Smith Durrant.
Mary and John had a further 2 children - Maria born in Reading, Berkshire and another James born in Middleton, Norfolk.
They settled in Middleton and can be found from the 1851 census onwards.
Charles Cove is listed on an 1851 living with an uncle and aunt in East Winch, Norfolk
He then changes his name to Charles Durrant and in 1861 is living down the road from Mary and John with his wife Eliza in Middleton.
Hope this helps