At the left you see her with Troel.
Troel was a poodle who lived in the street for only one season. The reason she left was that the writers thought she was to girlish. She was Tommies best friend before Ieniemienie.
She liked to play, but was scared to get dirty or to make jokes.
When ever there were trouble or problems, Sien listens to the muppets and poored in some tea with a biscket.
At the moment she is more like a regular mother then a problemsolver.