Found out courtesy of Big Finish.   Jacqueline Pearce ( guest appearances in Who on Tv & audios, Servalan on B7, and more) has passed away due to lung cancer.   https://www.bigfinish.com/news/v/rip-jacqueline-pearce   I know her mainly from Who ( though I hear she’s great in B7) . 

Thoughts & prayers to her family/ loves ones.