According to most sources on the internet, her year of death is unknown. One site did say she was killed on April 20th "in an unknown year." Thus we cannot calculate age.
From the Patron Saints Index: Daughter of a pagan chieftain. Converted to Christianity around age twelve, and dedicated herself to God. When ordered by her father to marry, she refused. Her father was enraged, and imprisoned her. She managed to escape, fled to Laon, Picardy in France, and lived as an anchoress in the forest. Her father dispatched agents to find her. They did, and when she refused to return and marry, she was beheaded. Locals built a chapel over her grave; it soon became known as a site of miracles, and the town of LaChapelle grew up around the site.
Pope Saint Clement I was born in Rome.
Silvia Saint was born on February 12, 1976.
Saint Bruno was born in 1030.
Saint Oda was born in 680.
Saint Non was born in 4##.
Saint Sabina was born in 0##.
Saint Mercurius was born in 224.
Saint Théobald was born in 990.
Saint Asaph was born in 5##.
Saint Armel was born in 4##.