Smith was headed for a liver transplant, but her health deteriorated and doctors said she was too sick to survive the procedure.
The video was posted on Facebook early Tuesday by Smith's daughter Megan Smith, and has been liked by 3.4 million viewers as of Friday morning. Smith wrote of the nurse.
Nuefelder said that the moment captured on video was an emotional one, "knowing that this could be the last time I was singing to her".
"This nurse sat with my mom for hours while the medicine from too much Anesthesia and sang a very special song to my sweet mother to comfort her".
"There was nearly a sense of peace knowing that it was her favorite song and she did tell me it's the song she wants played at her funeral", Neufelder told NewsChannel 5.
As you can see, nurse Neufelder is overwhelmed by emotion a couple of times, but she still urges Smith to smile and join in the song with her.
Smith was moved from the hospital to a nursing home in Cookeville, Tenn. "I wanted her to know that she was loved even if her family wasn't able to be there".
"Miss Marg has touched my heart in such an indescribable way." said Neufelder. (I hope you all share this so it can find its way back to nurse Olivia in Vanderbilt)'. Smith wrote in the post. "This experience has challenged me in many ways".
According to reports, Smith's mother passed away a few days after the video was taken and had battled liver cancer for a year.
A gofundme has been set up to help Smith's final expenses.