At the casino in Reno, Nevada, where they met several years ago, Stephen Paddock was a “big fish” and Marilou Danley a petite hostess.

“They were adorable,” Paddock's younger brother, Eric Paddock, told reporters this week. “He loved her. I mean he doted on her."

The brother was not surprised, then, by news reports that wealthy retiree Stephen Paddock may have sent $100,000 to the Philippines to be collected by Danley.

She was travelling there when her live-in boyfriend carried out the deadliest mass shooting in modern US history, gunning down 58 people at a Las Vegas concert on Sunday night before killing himself.

Danley, 62, returned to the United States on Tuesday and was being interviewed by Federal Bureau of Investigation (FBI) agents in Los Angeles. Authorities have called her a “person of interest.”

Two officials briefed on the case said that as of midday Wednesday, there was no indication she was aware of Paddock's plans.

Danley said in a statement read by her attorney Matt Lombard in front of the FBI's office in Los Angeles that she had no advance warning of the attack and that Paddock had sent her out of the country, telling her the money was to purchase a home in the Philippines for her family.

Eric Paddock also said Danley might not be able to give investigators any clues.

“Mary Lou (sic) is absolutely the closest person to Steve," the brother told Reuters in a series of text messages elaborating on their relationship. ”My fear is that he manipulated around her, and she's not going to know any more than anyone else does."

Danley has not been charged in the case and told her family she has a “clean conscience” following the Las Vegas attack, her brother said in an interview with ABC News in the Philippines.

The portrait emerging of her stands in stark contrast to that of Paddock.

While he had few friends and kept to himself, Danley is warm and outgoing, according to media interviews with family, neighbours and friends.

Danley was born in the Philippines and moved to Australia where she married and became an Australian citizen, according to The Gold Coast Bulletin, an Australian newspaper.

She was married for more than 20 years to her second husband, Geary Danley, and the couple moved to Nevada when they retired, The New York Times reported.

A voicemail recording for Sheila Darcey, Marilou Danley's daughter, directed reporters to her mother's attorney.

"She is a good and gentle person, and I know she has to be devastated by what has happened," Dionne Waltrip, the daughter of Geary Danley and Marilou's former stepdaughter, told KHOG-TV in Arkansas.

Marilou Danley described herself on her now-disabled Facebook as a “proud mom and grandma who lives life to the fullest.” Her account was full of photos with family members and trips overseas.

She was working as a hostess at the Atlantis Casino Resort Spa in Reno, Nevada's capital, when she met Paddock, a wealthy gambler, according to his brother.

The casino said in a statement only that she stopped working there "several years ago."

Paddock bought the newly constructed two-story house on Babbling Brook Court, a cul-de-sac on the edge of the small city of Mesquite in January 2015, state property records show.

Danley and her then-husband Geary Danley filed a joint petition for divorce in Reno a month later, according to court records.

She was sympathetic in dealing with Paddock's allergy-driven quirks, Eric Paddock told Reuters.

Paddock often wore brown cloth gardening gloves to prevent rashes from contact with cleaning chemical residues, the brother wrote.

Las Vegas shooting – in pictures Show all 15 1 /15 Las Vegas shooting – in pictures Las Vegas shooting – in pictures People scramble for shelter at the Route 91 Harvest country music festival after gun fire was heard Getty Las Vegas shooting – in pictures People carry a person at the Route 91 Harvest country music festival after shots were fired David Becker/Getty Las Vegas shooting – in pictures People run from the Route 91 Harvest country music festival after gun fire was heard David Becker/Getty Las Vegas shooting – in pictures A handout photo released via Twitter by Eiki Hrafnsson (@EirikurH) showing concertgoers running away from the scene (C) after shots range out at the Route 91 Harvest festival on Las Vegas Boulevard EPA/Eiki Hrafnsson Las Vegas shooting – in pictures People lie on the ground at the Route 91 Harvest country music festival after hearing gun fire Getty Las Vegas shooting – in pictures A man in a wheelchair is taken away from the Route 91 Harvest country music festival after hearing gun fire David Becker/Getty Las Vegas shooting – in pictures People stand on the street outside the Mandalay Bay hotel near the scene of the Route 91 Harvest festival on Las Vegas Boulevard EPA/Paul Buck Las Vegas shooting – in pictures FBI agents confer in front of the Tropicana hotel-casino after a mass shooting during a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Las Vegas police run by a banner on the fence at the Route 91 Harvest country music festival grounds after shots were fired David Becker/Getty Las Vegas shooting – in pictures An injured person is tended to in the intersection of Tropicana Ave. and Las Vegas Boulevard after a mass shooting at a country music festival Ethan Miller/Getty Las Vegas shooting – in pictures Metro Police officers pass by the front of the Tropicana hotel-casino after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures A woman sits on a curb at the scene of a shooting outside of a music festival along the Las Vegas Strip AP/John Locher Las Vegas shooting – in pictures A cowboy hat lays in the street after shots were fired near a country music festival in Las Vegas Getty Las Vegas shooting – in pictures Las Vegas Metro Police and medical workers stage in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Sheriff Joe Lombardo (2-R) speaking during a press briefing in the aftermath of the active shooter incident on Las Vegas Boulevard EPA

He was also allergic to many pills and was unable to renew his pilot's licence - he had flown planes since he was a teenager - because he could not take the pills needed to reduce his blood pressure.

At casinos where he was a regular, he was such a valued customer that staff obliged his requests to wash his room's carpet with plain water.

“The reason Mary Lou looks so plain in that picture they keep posting of her is because for him she would not wear perfumes or hair sprays or anything with scents in it because it affected him," Eric Paddock wrote, referring to a passport-style photo of Danley that has been widely circulated by news outlets.