Time for a tidy up to make it all easier to see.
William Boulger married Elizabeth Byrne 1857
Children so far
William 1857
Edward Joseph 1859 (assuming Edmund is the same person) married Frances Harvey 1888
Maria Georgina 1861 Married Richard Tyndall 1882, has more than one marriage.
Alice 1864 married Edward Thompson 1897
Mary Harriett 1867 married James Reid 1903
Elizabeth 1868
John 1872
Sarah 1875 married WJ Smith 1908
That could be all the children, no major gaps there, still it's only 8, you'd expect 10 or 11
William the father died 1908
Mother Elizabeth still alive in 1911.
Is that everything so far?