Louisa Watson Small was born in Keady, Armagh, Ireland and educated at Queens College, Belfast and the University of London.
Louisa helped Harold write Private Peat (1917), a memoir of his experiences during World War I and after.
He described himself as an ardent Prohibitionist but in the book he said he did not think the rum ration controversially issued to Canadian troops was dangerous.
With their three young daughters, Peat and Louisa toured the United States, both lecturing on the Redpath Chautauqua Circuit.
Peat's speakers included Winston Churchill, Robert E. Peary, Lady Baden-Powell, Thomas Mann, William Patrick Hitler, Lillian Hellman, Ilka Chase, H.G.