Meet Billie

Eleven years after Joe was born, Graham and Tracy Sugg had another baby girl who they named Wilma Hazel Sugg, or Billie for short. Sadly, they didn't have the money to support and raise the little girl, so they had no choice but to give her up. Almost fifteen years later, what will happen when a couple who are very close friends with Zoe and Joe end up adopting young Billie? Will the oldest Sugg siblings realise that their little sister is right under their noses, or will they never find out?