Huge help for parents of teens!

Recently started working my way through these podcasts and have found them super-useful for navigating my way through the teenage years. I have 13 year old twin girls who are best friends one minute and screaming at each the next! One of my daughters is very hard on herself when she doesn’t perform as well as she hoped particularly with things she loves, such as sports (she plays in a netball team) and her art work. But also with all her school work, tests etc. Would love some advice on how to help her through this.