'After the accident I wanted my old dad back'
Lottie’s dad was out riding his bike when he was hit by a car but his helmet, which is now used in police training, saved his life.
He suffered a serious brain injury which affected his memory and personality.
Lottie wanted to share her story with BBC Young Reporter to highlight the impact of an injury like this and how it can affect a whole family.
You can find stories by other young people on theBBC Young Reporterwebsite.