Merricat

How is Siobhan even connected to Project LEDA? Maria Doyle Kennedy is almost 50, so I'm assuming Siobhan is around that age. The picture Amelia had was dated July 22, 1977. That was 37 years ago, which would make Siobhan 13 at the time the picture was taken. Even if you age her up to 18 (making Siobhan 55 now, which... I don't know, maybe she's got great genes), I can't see where she fits in. The way she said, "They're Project LEDA" made it sound like she had a deep connection to whatever LEDA is or was, but... how? Am I just missing something super obvious?