Police say they consider the woman's claim a hoax, but refused to comment about where the finger originated and exactly how the hoax was carried out.
Anna Ayala is accused of attempted grand larceny, a charge authorities said relates to the financial losses Wendy's has suffered since Ayala claimed she bit down a finger tip in a mouthful of her chili on March 22.
According to a person knowledgeable about the case who spoke on condition of anonymity, the charge stemmed from San Jose police interviews with people who said Ayala described putting a finger in the chili.
The loss to Wendy's restaurants in the Bay area is $2.5 million, according to the felony complaint against Ayala.
The chilling message from this food contamination case is that a corporate reputation can be dangerously fragile, CBS News Correspondent John Blackstone reports.
"Indeed, what we have found is that thus far our evidence suggests the truest victims in this case are indeed the Wendy's owner, operators and employees here in San Jose," San Jose Police Chief Rob Davis said Friday.
Sales dropped at Wendy's in Northern California because of the furor, forcing layoffs and reduced hours.
"It's been 31 days, and believe me it's been really tough," said Joseph Desmond, owner of the local Wendy's franchise. "My thanks also go out to all the little people who were hurt in our stores. They lost a lot of wages because we had to cut back because our business has been down so badly."
Such claims can turn into corporate public-relations disasters literally overnight, CBS' Blackstone reports. So what is a company to do when faced with a claim that could lead to dramatic financial losses, regardless of legitimacy?
"The most important thing for Wendy's is to provide an alternative story," Ward Hanson of Stanford business school said.
The company plans to launch a marketing campaign and decided to offer free Frosties this weekend at its Bay area restaurants, Wendy's spokesman Denny Lynch said.
"If you look at the facts, the police have conducted an investigation and filed charges and made an arrest. We believe that is a clear sign we have been vindicated," he said.
Ayala's claim that she found the well-manicured finger during her meal at a San Jose Wendy's initially drew sympathy. She hired a lawyer and filed a claim against the franchise owner, but dropped the lawsuit threat soon after suspicion fell on her.
Ayala, who has a history of bringing claims against big corporations, was arrested at her suburban Las Vegas home Thursday. A court appearance is scheduled for Tuesday; in the meantime, she is being held without bail.
Many loyal patrons continue to support the Wendy's where Ayala made her claim.
On Friday, Tom McCready headed into the franchise and ordered two bowls of chili to go plus a baked potato topped with chili.
"If they've got 10 fingers, it's OK with me," the San Jose retiree said about the Wendy's employees at the counter.
He said he and his wife have supported the restaurant since Ayala's claim, heading there more often and ordering the chili. His opinion of Ayala's claim: "It's a crock."