Douglas was the son of Mr. Walton, a rich banister living in County Kerry, Ireland. In 1909 Margaret, then aged 16, began to work in the house as a maid and shortly after she started a romantic relationship with Douglas. In a conversation with her brother Eamonn years later Margaret remarks that he should have known about it, but he claims to be blind to those matters.
Margaret became pregnant and refused to tell her family who the father of the child was. When threatened to being sent to a Magdalene Asylum for "fallen women", Margaret falsely claimed to have been raped but was not believed. She appealed to Eamonn and when he refused to interfere she stole the money that the family had been saving to send Eamonn to America and went there herself. Margaret miscarried during the voyage. ("Peg of Old")
Since "Walton" is an Anglo-Saxon name, it's likely that Douglas and his family were descendants of English colonists in Ireland and therefore Protestants, making them even less likely to accept Margaret's child as their own.