Amy Hawkins' rendition of the popular World War One song It's A Long Way to Tipperary was captured by her great-grandson on her milestone birthday.
Since then Sacha, 14, has clocked up 100,000 views of the video.
Ms Hawkins, of Monmouth, was a performer and at Sacha's age toured the UK - but her mother banned her from the stage, as it was not "respectable".
Sacha's mother Hannah Freeman, said the reaction to the video on the social-media site has "restored faith in humanity".
