At the parties Jill Kelley hosted at her Tampa, Fla., mansion, guests frequently were treated to the indulgences of celebrity life: valet parking, string quartets on the lawn, premium cigars and champagne, and caviar-laden buffets.

The main recipients of the largesse were military brass - including some of the nation's most senior commanders - based at nearby MacDill Air Force Base.

Kelley flaunted her access to these military VIPs but also developed what family members called genuine friendships with some. Now her close connections to retired Gen. David H. Petraeus and Gen. John Allen, the top U.S. commander in Afghanistan, have brought them all under intense scrutiny in an unfolding scandal.

Federal investigators have said that Kelley's complaint about harassing e-mails - which eventually were traced to Petraeus' biographer - triggered the FBI's discovery of the general's extramarital affair and his eventual resignation from his post as head of the CIA. According to a senior defense official, Kelley, 37, also exchanged hundreds of e-mails with Allen, who has been ensnared in the case amid questions about whether he had "inappropriate communications" with her.

Kelley has not responded to requests for comment since her name surfaced as part of the controversy. Officials close to Allen strongly denied suggestions that the general acted inappropriately with her.

In an interview, Kelley's brother said the relationship between his sister and Petraeus was social and entirely platonic. "They were truly good friends for years," said David Khawam, a lawyer in New Jersey.

The investigations of Petraeus' and Allen's actions, nonetheless, have raised questions about how Kelley, a woman with no formal military role, cultivated such close ties to two of the nation's most revered generals.

One former aide to Allen, who like others spoke on the condition of anonymity given the sensitivity of the case, suggested that Kelley had become a de facto social ambassador among high-ranking personnel at MacDill, home to the U.S. Central Command and Special Operations Command.

"Part of the job is social in nature," including accepting and extending invitations, the aide said. "She was someone who was connective tissue to that world."

Friends said that Kelley has been a fixture at social and charity events involving Central Command officials in Tampa and that her life has often focused on the lavish galas she throws with her husband, Scott, a prominent surgeon in nearby Lakeland. Scott Kelley told grateful guests at various parties that he and his wife felt an obligation to share their good fortune by showing support for the military.

Behind the glamour, though, the couple were racking up substantial debt. Banks have initiated foreclosure proceedings on two of their properties - not including their six-bedroom home - and other creditors have sued them for tens of thousands of dollars in credit card debt, according to filings in Hillsborough County District Court. A lawyer who represented the Kelleys in the civil suits said he had not been authorized by his clients to discuss the cases.

The Kelleys' party-giving tradition began before Petraeus' stint as Central Command chief from 2008 until 2010, friends said, but after the general and his wife arrived, the two couples developed a genuinely close bond.

Jill Kelley and her twin sister, Natalie Khawam, often went shopping and out to lunch with Holly Petraeus, particularly when her husband was stationed in Afghanistan, the friends said. In a 2011 custody battle involving Natalie and her estranged husband, Gen. Petraeus and Allen submitted letters of support to the court.

"We have seen a very loving relationship - a Mother working hard to provide her son enjoyable, educational, and developmental experiences," Petraeus wrote, speaking on behalf of himself and his wife.

Federal investigators said Jill Kelley's closeness to Petraeus - captured in party pictures in local newspapers as well as online - may have explained why she received harassing e-mails from Paula Broadwell, with whom the general had an extramarital affair.

But Kelley's brother, David Khawam, said neither of his sisters had anything but a social relationship with Petraeus. He said Jill is a born giver who early on channeled her efforts into political fundraising and later to the military.

It is a quality, he said, born of the Catholic family's persecution in their native Lebanon; when he, Jill and Natalie were small children, the family fled to the United States, he said. They built a productive new life in America. "We feel we owe everything we have to this country," David Khawam said. "We're extremely patriotic."

Jill Kelley and her husband started a charity focused on cancer research and on granting "wishes to terminally ill cancer patients," according to 2007 tax documents. The documents show that, of the nearly $160,000 the group raised, it spent roughly half on meals, entertainment, and automotive and office expenses.

Kelley has seemed eager to make her civic involvement clear to those around her. Outside her two-story mansion on Tuesday was a gray Mercedes-Benz S500 with vanity plates reading "Honorary Consul" and "1JK." Nearby, contractors were piling up tables and folding chairs after a weekend party.

A military officer who is a former member of Petraeus' staff said Kelley was a "self-appointed" go-between for Central Command officers with Lebanese and other Middle Eastern officials.

Her presence was often a bit puzzling to Petraeus' staff, the officer said, but added that there was never any indication that her relationship with the general was anything more than social.

Aaron Fodiman, the publisher of Tampa Bay Magazine and a friend of the Kelleys, said people in the family's social sphere are shocked by the spotlight that the investigations have cast on the community.

"She is so gracious, so lovely," he said of Jill Kelley. "She's one of those people - she walks in the room, and the room lights up."

Londoño reported from Tampa. Anne Gearan, Rebecca Cohen and Alice Crites in Washington contributed to this report.