More information is coming to light about Stephen Paddock's Australian girlfriend Marilou Danley, who police have named as a "person of interest" in their investigation.

She was born in the Philippines but also holds Australian citizenship and spent several years living in Queensland.

Now 62, she moved to the US following the death of her first husband.

Her former step-daughters have told US media they were shocked to hear of her association with Paddock.

"Our family doesn't know Stephen Paddock and has had no knowledge of Marilou's relationship with Mr Paddock," former step-daughter Dionne Waltrip told US media outlets.

"'Marilou is our ex step-mom. She is a good and gentle person and I know she has to be devastated by what has happened."

"She is kind. She's very gentle. She's very giving, she's always happy. She's just extremely nice and fun to be around. "

Deirdre Terrell, her other former step-daughter, said: "She's not harmful. She's not a bad person at all,' Deirdre Terrell, her other former step-daughter, said.

Danley, who is travelling in the Philippines, has been in contact with investigators and is expected to return to the US on Wednesday.