She previously worked in a crisis centre for people presenting with suicidal ideation/self harm. Derville has extensive experience in working with self-harm and suicidal ideation. She has developed programmes for schools and colleges addressing self-harm. Derville also teaches Mirror Therapy to therapists which is a valuable tool when working with eating and body image disorders. Derville worked for many years in a youth organisation in the community, counselling young people and their families. In recent times Derville has run groups for couples aimed at improving communication which were well received.