Investigators have focused on Danley, an Australian citizen who had shared his retirement community condo in Mesquite, Nevada, northeast of Las Vegas, before leaving the United States for the Philippines on September 15.
She says he wired her money while she was there to buy a house for herself and her family.
On Oct. 3, two days after the shooting, Danley returned to the US met by federal agents.
"The FBI has coordinated with the Philippine office of the Interpol to look for her", NBI spokesman Nick Suarez told AFP.
They described her as a "a good person" who would have stopped Paddock had she been there. "She was away so that she will not be there to interfere with what he's planning". "[She] didn't event know that she was going to the Philippines until Steve said, 'Marilou, I found you a cheap ticket to the Philippines", she claimed.
But he said Paddock's motivations and whether there were any possible accomplices remained a mystery.
At a news conference on Thursday, officials also confirmed Paddock had earlier rented a room in downtown Las Vegas about the same time as a music festival headlined by Lorde.
The local authorities in Las Vegas have said that the mass shooting of around 600 people, which killed 59, was premeditated and pre-planned. Paddock sent tens of thousands of dollars overseas before the shooting, ABC News reported Monday.
Her lawyer Matthew Lombard spoke in Los Angeles, where she had arrived after flying from the Far East where she had been visiting family.
"He manipulated her to be completely as far away from this and safe when he did this", Eric said.
The investigation into the motives of the mass shooting turned to the gunman's girlfriend in the Philippines, where she turned up after the massacre, authorities said.
Janette Henry used to consider Marilou Danley family.