I only have additional information on two of Robert and Sarah's children.
Robert Lowthian, my great grandfather, moved to Dublin, married, and had 3 children.
They all moved to the United States around 1914.
William Lowthian also moved to Dublin, married, and had a child.
They moved to Canada where additional children were born.
I found Robert and William and William's future wife, Leonie Muisier, on the 1901 Irish Census.
They all lived in Dublin at the home of John Murphy from Wexford. William and Robert are listed
as boarders while Leonie is listed as a visitor.