who was ann from an old tv show whose line is it anyway

The “Ann” you’re probably thinking of is Anne Wheeler , a recurring performer on the British version of Whose Line Is It Anyway?.

On the better-known American version, the main familiar names were Drew Carey, Aisha Tyler, Wayne Brady, Colin Mochrie, and Ryan Stiles rather than someone named Ann. If you meant a different “old TV show” or a specific sketch, the name may be from the UK run or from a guest performer rather than a regular cast member.