How long has Jessie j been a singer?

Jessica Ellen Cornish (born 27 March 1988), known professionally as Jessie J, is an English singer, songwriter and actress. Known for her distinctive voice which blends elements of pop, R&B, soul and hip hop, Jessie J has been performing since 2006. She came into the spotlight in 2011 with her debut single, "Price Tag".

So Jessie J has been a singer for around 16 years.