On a patch of sidewalk, within earshot of a one-legged man grousing about the lack of buses, Rebecca LaFlure knelt down and opened her box of colored chalk.

A little later, a figure bloomed on the gray-green canvas — cartoon bright, like a child’s tattoo: Arthur, the beloved aardvark.

Every so often, LaFlure flicked her blonde hair out of her eyes. When she looked up, the side of her head was flecked with coral and purple chalk.

Mamas and nannies pushing runny-nosed infants in strollers on this stretch of Montrose Avenue on the North Side stopped to marvel at her work. A man selling the magazine “Streetwise” dropped a free copy on the ground.

“I love that!” he said.

No one asked how LaFlure manages to draw so well. Perhaps they hadn’t noticed that her chalk hand has no fingers and only a nub for a thumb. She lost them in a horrific car crash in Texas 15 years ago. Hard to imagine, too, that the “Neighborhood Chalk Lady,” as she calls herself, is by day a corporate investigator. She might be asked to look into the criminal history of someone stalking a CEO. When companies are considering a big business deal, she often has to check out the background of the executives involved in the deal.

“The people I work with as an investigator, they think it’s hilarious,” LaFlure, 36, said of her hobby.

The hobby began in the early days of the pandemic as she searched for a safe way to get her 2-year-old daughter out of the house. Since then, she’s brightened hundreds of dreary sidewalks in her North Side neighborhood, chalking everything from cartoons to movie characters to a copy of a Picasso painting. She has an Instagram page: @chalkofthetown312. For a small fee, she’ll chalk for kids’ parties and has given a school talk about her art.

Jordan LaFlure — her husband and the managing editor of the satirical publication, The Onion — said he knew nothing about his wife’s talent before she began chalking.

“She started whipping these drawings out and I was flabbergasted,” he said. “I thought I knew my wife pretty well. She had this whole hidden talent.”

Rebecca LaFlure, who is from Texas, remembers little of the accident that took her fingers in 2007. She was a student at Baylor University and a passenger in a friend’s car on the freeway. The friend swerved to avoid a merging semitruck, LaFlure said. The friend lost control of the car and it flipped, traveling across the six-lane freeway. LaFlure’s arm flew out the window.

As the paramedics loaded LaFlure into a helicopter, one asked what she did for a living. A student and working toward becoming a journalist, she said.

“Well, now you have something to write about,” the paramedic said.

Surgeons tried unsuccessfully to reattach LaFlure’s thumb and one of her fingers.

LaFlure finished college and went to work for a small daily newspaper in Texas, managing to type with just one hand and using a tape recorder for notes.

“There was definitely a period where I was just kind of embarrassed of [the hand], which sounds really awful to me now. I would always wear this very realistic prosthetic everywhere I went,” she said.

That changed after she wrote a story for her paper about a camp for kids with hand “differences.”

“These kids are awesome. I would never want them to feel like they had to hide their hand. Why am I hiding my hand?” LaFlure remembered thinking.

She later moved to Illinois to get a master’s degree in journalism from Northwestern University. She chose to use the skills she learned in the corporate world.

When the pandemic hit, LaFlure was desperate for a way to cool the cabin fever. She loved to draw as a kid. Maybe, she thought, she still could. So she bought some brightly colored chalk and had a go on the walkway to her house.

She found she had enough of her thumb to grip the chalk against the side of her palm. Her drawings weren’t great at first.

“Since then, I’ve certainly gotten a lot better with practice,” she said.

And passersby have noticed too.

“It brightens my day when I see her out,” said Sheila Simhan, stopping with her stroller and two small children, as LaFlure brushed away the excess chalk dust from her Arthur drawing. “I love the colors.”

If it doesn’t rain or snow, LaFlure’s drawings can last for weeks, she said. She’s been known to touch up the smudges on her sidewalk art.

Sometimes, people don’t see the chalk and become alarmed at a woman hunched over on the pavement.

“They say, ‘Sorry, I thought you were having a medical emergency,’” LaFlure said.

Occasionally, a drunkard might approach.

“Can I take you for a dance?” a man once asked her. She declined.

While LaFlure was drawing last week, some pedestrians wore gloves and winter coats. Though her hands were pink with cold, LaFlure didn’t seem to mind.

Only snow, ice or rain keep her from her endless canvas.

When she’s drawing, she says, it blocks out her life’s stress.

“It’s been such a nice addition to my life, I don’t see myself ever stopping,” she said.