According Wikipedia the Rev. Carel ter Linden, the royal family's regular minister, he gave catechesis to the three sons of Queen Beatrix as well did their confessions:
Carel ter Linden 1933:
Confession Prince Willem-Alexander, Prince Friso and Prince Constantijn
Religious service for the marriage of Prince Constantijn of the Netherlands with Ms Petra Laurentien Brinkhorst, 19 May 2001, the Great- or Saint James' Church in The Hague
Religious service for the marriage of Prince Willem-Alexander, The Prince of Orange, with Ms Máxima Zorreguieta Cerruti, 2 February 2002, the New Church in Amsterdam
Religious service for the funeral of Prince Claus of the Netherlands, 15 October 2002, the New Church in Delft
Religious service for the christening of Eloïse countess van Orange-Nassau van Amsberg 15 December 2002, the Chapel of Het Loo Palace
Religious service for the wedding of Prince Friso of the Netherlands with Ms Mabel Martine Wisse Smit, 24 April 2004, the Old Church in Delft
Religious service for the christening of Princess Catharina-Amalia of the Netherlands, 12 June 2004, the Great- or Saint James' Church in The Hague
Religious service for the christening of Claus-Casimir count van Oranje-Nassau van Amsberg , 10 October 2004, the Chapel of Het Loo Palace
Religious service for the funeral Prince Bernhard of the Netherlands, 11 December 2004, the New Church in Delft
Religious service for the christening of Leonore countess van Oranje-Nassau van Amsberg, 8 October 2006, the Chapel of Het Loo Palace
Religious service for the funeral of Prince Friso of the Netherlands, 16 Augustus 2013, the Old Village Church, Lage Vuursche