When she returned, Riddle entered and won a contest in 1915 to complete the murals for West Philadelphia High School.
[2] Two years later, Riddle won a prize from Gertrude Vanderbilt Whitney for the "Friends of Young Artists' Exhibition" held in New York City.
[4] Riddle married Hans Kindler, a cellist and conductor, in 1920 and soon after the marriage the couple moved to Senlis, France.
[7] In 1939 Kindler was commissioned by the WPA to complete a mural for the post office in Ware Shoals, South Carolina.
The WPA was the largest and most ambitious American New Deal agency, employing individuals to carry out public works projects.