The nature of the relationship between Kelley and Petraeus is unclear. There is no evidence that they had any sort of romance.
Kelley serves as an unpaid social liaison to MacDill Air Force Base in Tampa, and from October 2008 to June 2010, Petraeus was commander of the United States Central Command, based in Tampa.
Petraeus staffers told the Associated Press that Kelley and her husband were regular guests at events he held at Central Command headquarters.
A U.S. official said the coalition countries represented at Central Command gave Kelley an appreciation certificate on which she was referred to as an "honorary ambassador" to the coalition, but she has no official status and is not employed by the U.S. government, according to the Associated Press.
Kelley is known to drop the "honorary" part and refer to herself as an ambassador, according the AP, quoting the official who spoke on condition of anonymity.
She began to receive the emails that she interpreted as threatening in May, according to the Wall Street Journal.
The FBI investigation began with five to 10 emails. Kelley didn't know who had sent them, but some appeared to accuse her of an inappropriate relationship, although Petraeus wasn't named, the Wall Street Journal reported.
In a statement issued Sunday night by Smith and Company, a Washington communications and crisis-management firm, Kelley acknowledged her friendship with Petraeus and asked for privacy.
She said that she and her family "have been friends with General Petraeus and his family for over five years."
She says she respects Petraeus' privacy and wants the same for her own family.
A 2010 society item in the Tampa Bay Times shows that Kelley and her husband, Scott, were friendly with David and Holly Petraeus. The Kelleys invited the couple to their brick mansion, estimated to be worth $1.37 million, for Tampa Bay's annual Gasparilla, a festival similar to a Mardi Gras.
Petraeus and his wife arrived at the Kelleys' home, escorted by 28 police officers on motorcycles. It was Petraeus' first Gasparilla celebration. Under a large white tent, guests munched on lamb chops, crab cakes, hot dogs and funnel cakes.
Petraeus called the celebration "awesome." "You have to see it to believe it, even in rain," Petraeus told the newspaper.
Kelley comes from a Lebanese family that lived in the small seaport of Jounieh, a resort town just north of Tyre. The family belonged to the Maronite Catholic Church, one of the oldest denominations of Christianity.
Kelley's parents, Marcelle and John Khawam, came to the Philadelphia area in the mid 1970s. Kelley has an older sister, Caroline, an older brother, David, and a twin, Natalie.
All the siblings now live in Florida except for David, who lives in Mount Laurel, N.J., according to public records. No family members could be reached for comment Sunday night.
John Khawam was a musician and considered a top organist in Lebanon. Marcelle was an accomplished cook who entertained people in the arts and politics, according to a December 1988 Philadelphia Inquirer feature about Middle Eastern food for Christmas.
At that time, the family lived in the Northeast Philadelphia and ran a small Middle Eastern restaurant, Sahara, in Voorhees, N.J.
The family later moved to Huntingdon Valley and as Jill Kelley grew older, she moved to Philadelphia where she worked in public relations in 1998, before moving to Tampa around 2000 or so. Her twin, Natalie, moved to Tampa about the same time.
In 2003, the twin sisters taped an appearance on a new Food Network show - "Food Fight."
Natalie showed up wearing a Chanel blouse, leather skirt and Gucci heels and Jill donned Brooks Brothers black, according to the St. Petersburg Times. At the time, Jill told a reporter that she was putting her medical studies on hold to have a baby.
Natalie is now an attorney dedicated to representing whistle-blowers. She has a law degree from Georgetown University Law School, according to LinkedIn.
She is currently in a legal battle with prominent Tampa lawyer Barry Cohen, her former employer. She has filed suit against him, his law firm and other defendants, claiming sexual harassment and breach of contract.
Cohen owed her money, she said, and he failed to take action when she reported a sexual-harassment issue involving a financial officer who did work for the firm. Cohen has denied the charges and submitted documents that he claims is evidence to the contrary.
Kelley's husband is a surgeon at H. Lee Moffitt Cancer Center and the couple apparently is active in social circles. In January 2007, their daughters' ages were listed in an article as 4, 2 and 1.
Back then, the Kelleys were not enamored by Gasparilla. Jill Kelley told the St. Petersburg Times that when she and her family moved to Bayshore Boulevard three years earlier, neighbors had warned her about the annual parade.
So she hired security guards to patrol her lawn from 10 a.m. until 6 p.m., paying each guard $400. Then she stayed inside and tried to avoid peering outside.
"Ignorance is bliss," she told the reporter, laughing. "I don't want to know what's going on out there."
But for this year's celebration in February, the Kelleys welcomed officers from 60 nations to their third Gasparilla Coalition Appreciation Party.
In the meantime, members of Congress said they want to know more details about the FBI investigation into the affair between Petraeus and Broadwell. They want to know specifically whether national security was in any way compromised and why they weren't told sooner.