Mentor was first selected for the senior England squad in November 2000 when she was aged 15. She was initially spotted by Lyn Gunson and her ability was recognised by England coaches, Julie Hoornweg and Wai Taumaunu. She made her senior debut on 11 July 2001, aged 16, against New Zealand. On her debut she marked Irene van Dyk. In 2002, Mentor featured at her first Commonwealth Games and in 2003 she played at her first Netball World Cup. She was subsequently a member of the England teams that won the bronze medals at the 2006 and 2010 Commonwealth Games and at the 2011, 2015 and 2019 Netball World Cups. She captained England at the 2015 Netball World Cup. Mentor was a prominent member of the England team that won the gold medal at the 2018 Commonwealth Games. In 2019 she was awarded the for her services to netball.