Marie-Gabrielle was born prior to her parents marriage and held no title at birth. Prince Jean had renounced his right of succession to the throne of Luxembourg prior to his marriage. On 21 September 1995 the wife and children of Prince Jean were elevated to Count(ess) of Nassau. On 24 November 2004, Prince Jean's children were granted the style and title of "HRH Prince(ss) of Nassau".
Marie-Gabrielle has three younger brothers: Constantin (born 22 July 1988), Wenceslas (born 17 November 1990) and Carl-Johan (born 1 August 1992).