Guess the age of this sexy grandma who is competing with 18-year-olds for a beauty pageant

Stunning grandma, Gina Stewart has left people baffled due to her extremely youthful appearance with many wondering how old she is.
The blonde single mother who is battling against 18-year-old models to be crowned Miss Maxim Australia is actually 47 years old and has four children, two daughters and two sons, who are 27, 25, 23 and four, and also has a 10-month-old granddaughter.
See more photos below.