Charlotte Platt is the daughter of Martin Platt and Robyn.
Born in 2006, Charlotte was Martin's second child, and his first with his partner Robyn, born after the pair moved away from their lives in Weatherfield to start afresh in Liverpool.
In October 2007, Martin was unable to attend his adoptive daughter Sarah's wedding to Jason Grimshaw as Charlotte was unwell. In 2009 when David stayed with his dad for a couple of weeks, he got to meet his half-sister and spoke about her to his ex-girlfriend Tina McIntyre after returning home.
By March 2018, Martin and Robyn had decided to move once again in search of a new life in New Zealand which shocked David. At first, he was resentful that his father was moving away but eventually warmed to the idea of a new life after being raped by Josh Tucker. Martin was sceptical about David's decision to uproot his own family.
- References in the programme to Charlotte date back as far as 2006, however she was not mentioned by name until Episode 9411 (22nd March 2018).