However, the agent said authorities hadn't ruled her out as a person of interest.
Paddock, the man behind the deadliest mass shooting in modern USA history, killed himself after opening fire on a crowd of concertgoers from his hotel room on the Las Vegas Strip, killing 58 people and wounding more than 500 others.
New information about the October 1 Las Vegas shooting carried out by Stephen Paddock was unveiled on Friday. It said, "we have huge selection" in the Las Vegas area.
Later that day another email read: "We have a wide variety of optics and ammunition to try".
An email in response suggested trying a bump stock on a 100-round magazine rifle, saying it would be "a thrill".
FBI spokeswoman Sandra Breault in Las Vegas said late Friday she could not comment about Danley or the investigation.
Paddock's email address and the Gmail address had similar names, leading investigators to suspect that he may have been emailing himself, although they couldn't figure out why.
Investigators at the time of the filing had been unable to determine if Paddock was sending emails between two accounts both belonging to himself, or was communicating with someone else. The FBI special agent who signed the affidavit argued that since only that phone was locked, any information related to a criminal conspiracy would be found on it.
Though Danley has not been charged, investigators note that "she has been identified thus far as the most likely person who aided or abetted Stephen Paddock based on her informing law enforcement that her fingerprints would likely be found on the ammunition used during the attack". She told investigators her prints would likely be on the ammunition because she "occasionally participated in loading magazines". "Neither contained significant information that allowed investigators to determine the full scope of Stephen Paddock's planning and preparation for the attack", the documents said.
Federal Bureau of Investigation agents knew the gunman behind the deadliest mass shooting in modern USA history left behind big caches of guns, ammunition and explosives when they sought warrants to search his properties and online accounts.
Danely's attorney did not respond to a call or text seeking comment on Friday evening.
She notably deleted social media profiles in the hours after the attack.
One affidavit filed in the early days of the investigation made a reference to the gunman's health.
Investigators also revealed that Mr. Paddock may have been treated for "unidentified medical conditions".