Lori Maltby said her sister's body was so badly decomposed that authorities estimated she had been dead about 2½ weeks. A medical examiner identified Atkinson through a tattoo of her son's name surrounded by an image of praying hands that was on the back of her right shoulder, Maltby said.
Potter said the medical examiner's choosing to identify the body by tattoos, rather than dental records, sped up the process. The cause of death is still "undetermined."
Authorities have said Atkinson was found about 300 yards from her blue Toyota Scion xB at the Dock Flat Campground in Mantua. The terrain was so steep that search and rescue crews were called in to remove her body.
The cause of death, what she was doing there and how she got there remain a mystery. The sheriff's office is continuing to investigate.
Maltby said her family suspects foul play because her sister who had cerebral palsy could not have navigated the rocky, rugged terrain without her cane, which she left behind.
"There isn't something that is screaming at us that this is a homicide with a suspect," Potter said, adding that since it was an unattended death anything is possible.
Sheriff's officers are checking Atkinson's car for clues and DNA swabs. They are also screening new tips that have come in since the woman's death, and following up on old leads the Brigham City police department had in their missing persons case.
The family believes someone out there knows something.
"Jenny couldn't even step up on a porch without a cane or a railing system,"Maltby said. "We knew how she could get around."
Atkinson was found in an area where she would have had to hop a cattle fence and walk through rocky terrain. Family said she wasn't an outdoors type of person and rarely went anywhere by herself.
"There is not a chance in hell she would have gone where she was found," Maltby said.
The medical examiner's office told the family Atkinson did not have any broken bones, but she was found below a six-foot drop-off. A toxicology report won't be completed for several weeks, but the family is hopeful it will reveal more, Maltby said.
The missing person case was originally filed with Brigham City police on July 23. However, Maltby said that when Box Elder County Sheriff's deputies responded to the report of a body on Friday, it was the first time their office had heard of the missing woman. There are now four investigators for Box Elder County working on the case, which is classified as "suspicious."
"Jenny is in a wonderful place now," Maltby said. "To get over it I can't dwell on who didn't get things done."
The way Maltby copes with her little sister's death is to remember the qualities that made her shine.
"Everyone talks about her smile and just how happy and upbeat she was," Maltby said. "We just think about how happy she is now, rather than what she had to go through to get where she is now."
Funeral services for Atkinson will be Aug. 17 at 11 a.m. at Gillies Funeral Chapel, 634 E. 200 South, Brigham City, according to her obituary. Interment will be in the Brigham City Cemetery.
Instead of flowers, the family suggests donating at America First Credit Union under Jenny's name to help with funeral expenses and support her 12-year-old son.