An interesting 1850 marriage entry - 19.8.1850 at St Botolph without Bishopsgate
James Dorgan 27 bachelor - carpenter - father = John Dorgan occ carpenter
Jane Mahoney 37 widow - father Michael Collins occ farmer
So Jane appears to have been born as Collins, married O'Brien, then Mahoney , then Dorgan
Witnesses John Clark & ? Jane Watt