It has also been confirmed that The Princess of Orange's sisters, Alexia and Ariane, will use the same Standard when they come of age on their respective 18th Birthdays. This is not unusual as both King Willem-Alexander and his brothers and Princess Beatrix and her sisters share/shared the same Standard with their siblings whilst not Sovereign.
King Willem-Alexander also appointed his eldest daughter and Heir to two Orders of Chivalry by Royal Decree. On 24th December 2021, Catharina-Amalia was appointed Knight Grand Cross in the Order of the Netherlands Lion and, by tradition on her Birthday itself, she was appointed a Knight in the Order of the Golden Lion of Nassau, which is jointly governed by the King of The Netherlands and the Grand Duke of Luxembourg.
To mark the occasion, The Princess of Orange was invited to plant a royal lime tree in the French Garden of Kneuterdijk Palace.