Lady Sylvia Creighton-Ward (better known as Great Aunt Sylvia) appears in the Thunderbirds Are Go! episode Designated Driver. She visits Creighton-Ward Manor to inform her great-niece, Lady Penelope, about the T.E.A.
She and her husband, Lord Creighton-Ward, are the fourth-richest couple in Europe. She's quite demanding and brave, and is used to getting what she wants - and acts the part.
- Great Aunt Sylvia is based on, and voiced by, the late Sylvia Anderson - the original inspiration (and voice artist) for Lady Penelope Creighton-Ward in the classic Thunderbirds series.
- Her outfit pays tribute to the original Penelope's appearance in the classic episode The Duchess Assignment.
- She's the only other member of Lady Penelope's family to appear in a Thunderbirds series.