High Quality Content by WIKIPEDIA articles! Heather Jean Chasen (born 20 July 1927) is a Singapore-born English actress. Her best known roles are playing Valerie Pollard in the ITV soap opera Crossroads (1982–86) and voicing many roles in BBC Radio 2`s The Navy Lark (1959–77). She was in the soap opera Marked Personal, in which she played one of the leading characters alongside Stephanie Beacham and in 2011 she was cast as Lydia Simmonds in the BBC soap opera EastEnders, replacing Margaret Tyzack (who had pulled out of the role for personal reasons). She departed on 13 June 2011, after doing a voice-over for the 14 June episode.