Berenyi owned a TARDIS which she took from Gallifrey when she "disappeared," tired of the restrictions of her world and her people. At some point in her life, she became a Designer "out of spite" and used the TARDIS to help her make changes in the timeline as she took work from wealthy clients to alter events to their liking.
Berenyi's TARDIS had previously visited the year 1865 when the Time Lady had been hired to Design an assassination in a theatre, which attracted the German from the 22nd century who hired her to Design President Kennedy's assassination. Berenyi left 1963 in her TARDIS before the police could arrive the Texas Book Depository which was where the shooting came from. (PROSE: Untitled)