I think Hayley Atwell who played Agent Peggy Carter might make a good lady Dr Who.
BBC News article: Doctor Who: Who could replace Peter Capaldi?
http://www.bbc.com/news/entertainment-arts-38808070
DailyMail article: 'It's time to move on': Peter Capaldi reveals he is QUITTING Doctor Who... a month after claiming he wanted to stay for a 'long time'
http://www.dailymail.co.uk/tvshowbiz...octor-Who.html