Siddy is rightly recognised as one of Britain's finest glassblowers. She embarked on a three year apprenticeship under Peter Layton at the London Glass Blowing Workshop in 1979, working with him for a further five years before opening her own studios in Maidenhead in 1987. She left Maidenhead ten years later to open her current studio in Devon.
Siddy fashions each piece from molten glass incorporating metals such as gold, silver and tin. Each signed and dated piece is unique. Decoration is applied before the glass is blown, then grows with each piece to form delicate and intricate patterns. Her work is exhibited both at Marine House and at Steam Gallery.