|Constantin, Katy, and their son Félix on the occasion of their marriage.
Prince Constantin and Princess Kathryn de Nassau welcomed the birth of their second child and first daughter, Princess Cosima, on 13 May 2022. Cosima joins older brother Prince Félix (b.2018). Prince Constantin de Nassau and Princess Kathryn (née Mechie) married in 2020. Prince Constantin is the son of Prince Jean of Luxembourg and his first wife Hélène Vestur; the prince is the nephew of Grand Duke Henri of Luxembourg. Kathryn Mechie is the daughter of Stewart Campbell Mechie and Kaye MacEwan.