Caitlin Blackwood starred in the opening episode of the new season of Doctor Who, playing the younger version of the Doctor's new companion Karen Gillan - who is her cousin.
Karen Gillan begged 'Doctor Who' bosses to cast her cousin in the show - even though they had never met.
The Scottish actress - who portrays the Time Lord's new assistant Amy Pond in the upcoming series of the sci-fi show - met her young relative, the now 10-year-old Caitlin Blackwood, for the first time on the set of the BBC One show after urging producers to let her play a younger version of her character.
Caitlin's mother Linda told the Daily Record newspaper: "Caitlin was born and grew up in Northern Ireland and Karen grew up in Scotland. So they actually only met for the first time at the read-through on set. It was an emotional moment. People kept commenting that they were so alike."
Caitlin said: "It was scary seeing myself up on the screen for the first time. I loved getting to know Karen and chatting with her. I got to meet some Daleks and went inside the TARDIS too."
Despite being cousins, Karen insisted the youngster had to go through a difficult audition process before she secured the part.
She added: "We didn't have many scenes together but we saw each other around set and that was really nice."