Tom, is this you?
When you say your wife's mother was born at 4 Kilarney Street, you've either got to be my dad or my uncle!
So, at No.4 Kilarney Street, we have
David John McKnight 1879-1961
Elizabeth (Lizzie) McKnight -nee Haire 1879-1954
Samuel McKnight 1904-1968
David 1907-1969
Elizabeth 1908-1916
Robert James 1911-1969
George 1913-1913
Hance 1915-1987 (he didn't have a middle name)
James 1917-1994
and
Grandma Isabella (Isobel)
In 1911 I have the family living at 24 Derry Street, so they must've moved sometime between 1911 and 1920 to Kilarney Street.
Also, David McKnight senior's mother, Elizabeth McKnight, nee Evans was possibly also living at Kilarney Street in 1920. She died in 1921 in hospital, but Kilarney Street is given as her address.
Depending on when they moved not all the above people would've lived at Kilarney Street, for example George and Elizabeth jnr may not have lived there.