This picture was likely taken in 1917. Kenneth would have been about 7 years old, Hazel about 5, and Agnes would have been about 1 year. Albert and Amy's fourth child, Frank, was born in July 1918. Two more children, Myra and Fred, were born to Albert and Amy in 1921 and 1928.
Thank you, Shari, for sharing your collection of Laabs photos!