Barbara Briley and her great-granddaughter, La'Myra, were lying on their backs near empty juice boxes and snack wrappers when Maj. William Knott approached them deep in a wooded area of southeastern Virginia on Wednesday evening.

La'Myra, 5, perked up from beneath a blanket and started crying. She said she and her great-grandmother had gotten lost while driving to visit family in North Carolina for Christmas.

Authorities had searched for at least three days for the two, who left Mays Landing, N.J., the morning of Christmas Eve.

"We're here to help you," Knott, an officer with the Dinwiddie County Sheriff's Office, said he told La'Myra, who had on a jacket and pants, but no shoes or socks. In the shock of the moment, she asked whether she was going to jail, Knott said. He assured her she was in no trouble.

Knott then asked Briley, 71, who was wearing jeans, shoes, and a coat, whether she could hear him. Briley's eyes opened and closed, and she mumbled, but no full words came out, Knott said.

Emergency responders placed her on a stretcher and then in the backseat of Knott's Ford Police Interceptor. He drove her to a nearby field, where a helicopter was waiting to take her to VCU Medical Center in Richmond.

She was listed in serious condition Wednesday night. Hospital officials said the family requested Thursday that her condition be kept private.

Knott marveled at Briley and La'Myra's luck as he recounted the discovery.

"The Good Lord was looking down on them," he said.

A property owner in Dewitt, nearly 300 miles south of Philadelphia, called police after spotting Briley's 2014 Toyota RAV4 on his land just before 5 p.m. Wednesday. The vehicle was at least a mile from Nash Road, a narrow street that cuts through farmlands, and more than three miles from I-85.

Virginia state police initially reported that La'Myra and Briley were found sitting against a tree, but Knott said they were lying on their backs.

He said he parked his vehicle and walked at least 25 yards through the thick woods to reach Briley and La'Myra, whose relatives reported them missing early on Christmas after they never showed up to a family gathering in Morven, N.C.

Knott said the car battery appeared to have died.

Authorities estimate that Briley and La'Myra were stranded for several days, with temperatures ranging from the 30s and 40s at night to the 50s and 60s during the day.

Investigators were still trying to determine Thursday when the two became stuck in the woods. State police said Briley had turned her vehicle onto a dirt road and then pulled off into the woods, where she drove over a small tree and tried to back up but could not.

The last time anyone had seen Briley and La'Myra was around 6 p.m. Christmas Eve at an Exxon station in Ruther Glen, Va., where Briley told an attendant she had become lost because of construction on the highway and could not get the GPS on her phone to work.

Briley's family last heard from her about two hours later, when she told her son on the phone that she was in standstill traffic near the split of I-95 and I-85 just south of Richmond.

That was at least 20 miles from where they ended up, and more than 230 miles from their destination in North Carolina.

The disappearance of La'Myra and Briley, a former NJ Transit bus driver described as a devout Christian, caused authorities to search highways, hotels, rest stops, and parking lots in Virginia and North Carolina.

Briley's family members, who also scoured the highways, said she had driven from Mays Landing to North Carolina many times before.

The discovery Wednesday came just as hope appeared to be waning.

Foul play is not suspected, authorities said.

Knott said La'Myra was talkative and seemed healthy. She was taken to the sheriff's office and reunited with family.

"She was in very good shape," he said.

On Facebook, the Briley family requested privacy but thanked the public and authorities for search efforts.

"Thank you everyone who has assisted our family during this time," the family said. "Our prayers have been answered."

mboren@phillynews.com 856-779-3829 @borenmc