Dorothy Palinchik was booked into the Pinellas County Jail on the eve of Valentine's Day, charged with stealing a $9 Philly cheesesteak from Publix.
Her boyfriend said he offered to pay her $250 bail, but Palinchik, 42, said she would rather do her time and get it over with.
Sometime over the next 10 days, Palinchik became gravely ill. On Tuesday, she was comatose at Largo Medical Center in critical condition.
The St. Petersburg woman is suffering from the staph infection MRSA as well pneumonia, her family said. Hospital personnel told relatives Palinchik has yet to respond to antibiotics and the prognosis is grim.
"I can't believe that over a sandwich my daughter is going to die," said her mother, also named Dorothy Palinchik.
Palinchik's mother, sister and boyfriend claim the jail ignored Palinchik's complaints and condition.
Sheriff's spokeswoman Marianne Pasha said laws prevent the release of details of Palinchik's treatment.
But when Palinchik was booked, she showed no signs of cuts or wounds that might have indicated MRSA, Pasha said.
An internal investigation is under way into Palinchik's treatment at the jail. Pasha said that is standard practice when an inmate becomes so seriously ill.
Researchers Caryn Baird and Shirl Kennedy contributed to this report. Jonathan Abel can be reached at email@example.com or (727) 445-4157.