Lillian Groves was killed outside her home by a speeding driver on cannabis in June 2010. Her family campaigned tirelessly to change the law on drug-driving, which came into to force last year and is known as 'Lillian's Law'.

Here Lillian's aunt, Michaela Groves, speaks out against the 'taboo' subject of drugs and says that people need to understand the consequences of drug driving.