“What knocked me for a loop,” she said, “was the death of my husband.” He had a fatal heart attack in 1991 while they were living in New Mexico, she said. Ms. Ritter did not want to say anything more on the matter and would not discuss her family. “Things just happened,” she said.

While she spoke, a worker from a bodega next door appeared with a cup of coffee for her. She thanked him. “She’s a nice lady,” another worker in the bodega said later. “I feel bad for her.”

Ms. Ritter sells pictures she colors with markers and signs “Marlo,” a combination of her first and middle names. She charges $20 a picture, and she has taped several samples to the window of the 7-Eleven.

A worker at the 7-Eleven came out to wash the windows on Thursday. “Excuse me, dear,” he said, cleaning around her drawings without disturbing them.

Ms. Ritter said she returned to New York in the 1990s, and while dates escape her, she was living on the streets by 2001. She knows this because she was rooting through a trash bin when she looked up and saw what she thought was a small plane hit the World Trade Center on Sept. 11. Then she called 911.

“You can bet that day everybody went to Heaven,” she said.

When Snap disappeared a couple of years ago, she looked for him for months in the course of her search for discarded valuables. Ms. Ritter got another cat, Simon, who would nudge her awake if anything was amiss, she said. But one evening last December, someone stole Simon, as well as her art and $303.

Then she found Snap in May — dead in a box. “On 30th and Broadway,” she said. Ms. Ritter had no explanation for the seeming mutilation, which she never reported.