It was the second federal lawsuit filed over the salmonella outbreak that has sickened hundreds of people in the region.
Jerri Reges, 39, of Cabot, said she bought a sandwich at the Sheetz on Center Avenue in Butler on July 5 and got sick the next day.
She was treated for severe dehydration and other symptoms at Butler Memorial Hospital and discharged after four days.
She said her illness forced her husband to miss a week of work and disrupted the lives of their two teenage children.
Last week, James Groves and his wife, Suzanne, of West Sunbury, Butler County, were the first to sue Coronet, saying they got sick from sandwiches they bought at a Sheetz on July 2.
The state Department of Health reported yesterday that 280 Pennsylvanians have been sickened in the outbreak so far, up 20 since Monday.
As of last week, health officials in West Virginia, Maryland and Ohio had reported another 73 cases likely tied to the outbreak.
Investigators are focusing on tomato contamination as the cause. Although it's not clear how it occurred, sliced Roma tomatoes were contaminated before arriving at Sheetz stores, health officials believe.
The Pennsylvania Department of Agriculture is continuing to collect samples from various sources.
Coronet Foods was the sole supplier of sliced Romas to Sheetz.
People started getting sick after eating from Sheetz stores during the first 10 days of July.
Further tests will determine which of the cases being reported now can be linked definitively to the outbreak.