In the late 2010s, Guerra turned to editorial cartooning. She has done cartoons for the online page "The Nib", "The Washington Post" and "The New Yorker". Following the February 2018 mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida, she posted a widely shared cartoon on Twitter depicting school staffer Aaron Feis, who had died protecting students, being led in the afterlife to a hero's welcome from those who had been killed. Guerra told "The Washington Post" that the cartoon was a direct response to her feelings of helplessness in the face of yet another mass shooting.