Bowerman trained at the Bristol Old Vic Theatre School, and was a regular in the first two series of BBC medical drama Casualty playing Sandra Mute, the show's first female paramedic. Her other television work includes: Dodgem, The Count of Solar, Grange Hill, The Vision Thing, Doctors, McCallum, Bad Girls and Night and Day. In 2007 she guest-starred as the Home Secretary's PA in Spooks, and returned to Casualty for a one-episode cameo role as a patient.
She has recorded many plays for BBC Radios 3 & 4, and has worked extensively in theatre.
Bowerman played the role of Karra in Survival, a serial in the British science fiction television series Doctor Who in 1989. Since 1998, she has played companion Bernice Summerfield in the Big Finish Productions' Doctor Who audio plays. She also appears in two Doctor Who audio plays opposite Sylvester McCoy as the Seventh Doctor and Sophie Aldred as Ace, as well as in over 50 audio plays based solely on Bernice. Other audio play characters include Ruby in the Sapphire and Steel stories Water Like a Stone, Cruel Immortality and Second Sight, and Murash in I, Davros: Guilt and Ellie in Jago & Litefoot. She has also directed many other Big Finish audio dramas. She also voiced Saruba Velak in Dreamland for the BBC.
Bowerman is also a professional photographer, the House Committee Chair Denville Hall the retirement home for actors, and a trustee of The Actors' Charitable Trust.