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The 1861 census shows John and Hannah's eldest child as aged 13, so their marriage will be this one:
Dec 1845 Wimborne
John Fry
Hannah Seller
It may have been a double wedding as the other couple marrying were:
Joseph Seller
Mary Ann Gallop
1841 census HO107/289/7
Sturminster Marshall
Richard Seller, 40+, ag lab, Y
Elizabeth Seller, 45+, Y
Emily Seller, 15, Y
Anna Seller, 13, Y
William Seller, 11, Y
Ellen Seller, 9, Y
Francis Seller, 6, Y
None of the children was at home in 1851, but Eliza P Fry was visiting.
Richard
1851