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The Liverpool born children according to censuses and GRO:
1849 Mary J. birth Mary Jane 1848 mmn Crann
1855 Thomas
1856 Catherine birth 1856 mmn Cram
1859 Mary
1863 Ann. Birth 1861 mmn Cran
The spellings vary and looking at the gaps in the years, there could be more.
There are several Catholic baptisms with Mary’s surname with variations of ‘Cran.
This might then be the marriage:
https://registers.nli.ie/registers/vtls000633984?locale=en#page/139/mode/1upFebruary 3rd 1842 Taunagh/Riverstown, Sligo