Hello Mary45
So to recap...
1859 Charles baptised St Marys Consett (who were his parents? could we try and find them in the censuses to get a handle on the surname)
1865 Mary Gallagher born Newcastle upon Tyne, father Michael, probably from Ireland (where did the Ireland bit come in? who was her mother? have you found them in any census records?)
1887 Ethel born
22 October 1887 Mary Gallagher marries Charles Valleny, witnesses A Patrick & Maria Cullen (living at 41 Mosley Street with Mary G.)
26 February 1889 Ethel 'Valleney' baptised St Marys Clayton Street Newcastle, adoptive daughter of Charles & Mary 'Valleney'. Valleney also written in register as 'Vanelly'. Godparents were Thomas Harrison & Mary Vanelly
1891 Charles dies aged 32
31 March 1894 Mary 'Vallaney' marries James O'Connor at Heworth Gateshead, both living at 11 Providence Place Felling
1901 Census possible sighting of Ethel
1904 Ethel 'Vallaney' marries
Have you found any Gallaghers or Vanelly/Valleney on any census record? I did look for any Charles born in Durham between about 1859 but the nearest I could come up with was a Varley, who was happily married and still alive in 1891.
I have also found a Mary Ann Valleny on freeBMD born Sept 1858 Durham 10a 222, with her possible sighting in Heworth in 1861 (Valleby), father Patrick, mother Catherine in Heworth.
All good stuff.... Any more names would be great to narrow them down.
Tracy