For 2017's National Day in Luxembourg, only Grand Duke Henri, Grand Duchess Maria Teresa, Hereditary Grand Duke Guillaume, and Hereditary Grand Duchess Stephanie took part in the public celebrations. 

For the National Day Te Deum service at Notre Dame Cathedral, Stephanie wore a hot pink Georges Rech dress that came to the knee. It also featured a cape like backing with a jeweled neck. She carried a metallic silver clutch and wore matching heels. Her hot pink hat was by the France based milliner Sylvia Martinez of Les Folie’s Bibis. 

National Day in Luxembourg is celebrated over two days. Day one begins in the evening with the traditional torchlight procession. On day two, there is a Te Deum service with representatives from different faiths in Luxembourg, as well as an official reception at the Grand Ducal Palace. Additionally, there is a military parade earlier in the day. 

Usually, more members of the Grand Ducal Family take part in the festivities. It is not known why only the four took part last year, but some suspect it was due to the announcement that Prince Louis and Princess Tessy were divorcing earlier in the year. Louis would have been at the events solo, and therefore, drawing attention to the ongoing divorce. 

National Day in Luxembourg is on June 23 with the festivities starting on the evening of the 22nd.  You can read more about National Day in Luxembourg, here.