Sidonia is the real aunt of Wiske and parent figure to both Wiske and Suske. She is of noble blood but despite of this she didn't have much money. But all that changed when she won the lottery and didn't have to worry about money anymore.
Sidonia made her first appearance in the comic book De Avonturen van Rikki & Wiske in 1946 bij Standaard Uitgeverij. She was created by writer and artist Willy Vandersteen who gained the title of spiritual father to Suske & Wiske.
Sidonia is a very skinny and tall woman which she is often made fun of. She's always single and is always trying to find a man, although she does have an everlasting crush on Lambik. She used to wear a hat but this was changed in later comics.
Sidonia is of noble blood, which began in medieval times when her namesake Sidonia, a humble girl who delivered herbs and plants to the court of King Poefke, married that same king.
Another forefather of Sidonia is Baron Van Stiefrijke who lived in the 1800s.
Sidonia's father is nicknamed Snor (Moustache) and is living in a home for elderly people.
Sidonia has a niece called Carmencita Falasol who moved to Spain and a nephew named John who moved to Alaska.