"I didn't want to think she wasn't breathing," Siefer later said in an interview.
She called 911 while Harmon and shoppers at Clackamas Town Center in Happy Valley began giving young Audrey CPR.
"And it felt like forever but it was within seconds there were deputies there to save her life," the mother said.
Surveillance video shows sheriff's deputies running through the mall to reach Audrey.
UPDATE - @OHSUDoernbecher tells us Audrey’s breathing tube has been removed. The 15-day-old little girl had been on one since choking and losing her pulse on Sept. 30th at Clackamas Town Center #KOIN6News pic.twitter.com/g22xP8XuFX— Cole Miller (@ColeKOIN) October 10, 2018
"It looked bad and we didn't know how long she had been without oxygen," said Deputy Jonah Russell.
Her parents could only look on.
"You can't describe what it's like to see your child turn blue and not really know how to help or what the hell is going on," Harmon said.
The deputies got Audrey to burp up some fluid -- and get a pulse back. Firefighter-paramedics with the Clackamas Fire District arrived at the scene and transported the days-old baby to the hospital.
The emergency responders visited the family at the medical facility on Sunday.
"She had her eyes open and she actually grabbed on to my hand and it made me tear up pretty strong," Deputy Jonathon Zacharkiw said.
The parents won't soon forget that day -- and they won't forget those who gave their little girl a second chance.
"Thank you," Harmon said tearfully. "That's honestly, I mean how do you say thank you to somebody who saves your child's life when they're, as far as you can tell, not with you anymore. You can't thank them enough."