Wendy was killed off in the hospital drama's first week back for 2016, after a Christmas cliffhanger which saw gunman Gareth Hutchings let loose on a room full of hostages.
She died days later from a stroke caused by a bullet wound to the head.
As she uttered her final lines on the show: " I think I've been shot," the tears she cried were very real.
More from Spy:
• Another year! High-profile couples celebrate anniversary
• Maria Tutaia a beach babe once more
"When we were rehearsing before we filmed that final scene, Amelia, who plays Bella, was kissing my forehead saying, 'this is from Jasmine' and 'this is from Evan'. I had tears streaming down my face," Nairn told Women's Weekly.
"Amelia was saying 'you can't do that!' I told her, 'if I get it all out now, I can concentrate on just trying to play dead in the take'."
- nzherald.co.nz