Her father was known to visit the House of Lungbarrow, and the Eighth Doctor speculated that he may have encountered the young Cavis at this point. She had messy blonde hair and a ruthless personality; she was known for having taken on Sontarans and survived.
Cavis and Gandar were both completely loyal to Lady President Romana, resorting to ruthless methods to fulfil their missions. She had been on over thirty missions without regenerating, but died when she was decapitated and stabbed in both hearts, rendering her incapable of regeneration. (PROSE: The Shadows of Avalon)