Caitlin Blackwood
From Tardis Wiki, the free Doctor Who reference
Caitlin Blackwood played the young Amy Pond in The Eleventh Hour and The Big Bang. She is the cousin of Karen Gillan, who plays the older Amy Pond (although they had never met until Doctor Who). It was Gillan who convinced producers to allow Blackwood to play the role, although she had to go through auditions first.