By Saskia Rowlands The devastated mum of one of the four teens killed in a camping trip tragedy is calling for stricter laws foryoung drivers. Crystal Owen’s son Harvey and three pals drowned when their car swerved into a ditch and overturned. Three months on, Crystal wants a ban on drivers under 25 carrying passengers until a year after passing their test. Crystal, 39, says the lads could still be alive if the driver had been more experienced. She told us: “I’ve cried so many tears my eyes are raw. As a family we will struggle to ever come to terms with this loss, a life so full of promise cu…