She is best known for playing headmistress Mrs Bassinger in the long-running BBC school drama, Grange Hill, from 2003-2006. The character's first name has never been revealed, but according to the sign outside her head teacher's office it starts with "S". Mrs Bassinger was not seen during the 2007 series, her function in the programme taken over by Cathy Tyson as deputy head, Miss Gayle. It is not known if Boatswain will return to Grange Hill.
She also has extensive stage experience.