Before getting into cannabis, he had managed a car dealership in his city of about 20,000 people, about 100 miles southeast of Seattle. He was involved in the Rotary Club and had helped found the youth football league.

While Mr. Hendrix’s mother-in-law has eased her stance over the past few years, asking him questions and clipping articles on the topic, some relatives still won’t broach the matter.

“You know the usual chitchat, like ‘How’s your business going?’ ‘How’s your work?’ I don’t get any of that,” he said.

It has been stressful. “We know we entered a controversial world,” Mr. Hendrix said, “and we’re dealing with it the best we can.”

While a typical entrepreneur’s worst fear may be bankruptcy, the stakes are greater with cannabis. Despite growing acceptance, marijuana remains a Schedule 1 substance, like heroin, meaning the federal government regards it as having no currently accepted medical use and a high potential for abuse. If the Trump administration decided to prosecute cannabis businesses, entrepreneurs could go to jail and forfeit their property, said Allison Margolin, a lawyer in Beverly Hills, Calif., who has focused on cannabis law for the last 16 years.

The immediate response of Ms. Tingler’s parents to her news was fear. “I was a single mother, and they thought I’d lose my kids,” she said.

The Justice Department, however, has not gone down this path. Ms. Margolin said she knew of zero federal prosecutions of people conducting licensed marijuana activities in the last few years, unless they were also participating in illegal activities as well. In fact, her practice now focuses more on cannabis contracts and due diligence than criminal cases.