Nijhuis took part in the European Short Course Swimming Championships 2003 in Dublin, Ireland where she won a bronze medal in the 4×50 m medley alongside Hinkelien Schreuder, Chantal Groot and Marleen Veldhuis.

At the European Junior Swimming Championships 2004 in Lisbon, Portugal she won two gold medals in the 50 m, breaking the national record of Madelon Baans, and 100 m breaststroke.

In December at the European Short Course Swimming Championships 2004 in Vienna, Austria she won a gold medal in the 4×50 m medley together with Schreuder, Dekker and Veldhuis breaking the world record.

During the European Short Course Swimming Championships 2005 in Triest, Italy she once again broke the world record in the 4×50 m medley, with the same team as the year before.

In the 4×50 m medley she won a gold medal alongside Ranomi Kromowidjojo, Hinkelien Schreuder and Marleen Veldhuis equalling the world record that was set by Australia.