In 2004, she was an assistant of Dutch Head Coach Marc Lammers at the 2004 Summer Olympics in Athens, Greece, when the Netherlands won silver.

Annan's former husband Max Caldas previously coached the Netherlands women's team to a gold medal at the 2012 Olympic Games.

[8] In 2022, Annan was fired as coach of the Netherlands women's team after an investigation into accusations of verbal intimidation and creating a culture of fear and silence.

Several experienced players reported the decision had been made without consulting them, using hockey.nl to express their support for Annan and describing her as a "fantastic coach" (English translation of the Dutch original).

[3] Annan chose not to comment publicly, beyond releasing a statement that "In recent months I have gained insight into the points that we as a team, staff and individuals could work on.