[2] In October 1959, at the time of the Cuban Revolution, Mestre's parents left Cuba with their children because the new government headed by Fidel Castro confiscated their properties.

[5] On 19 April 2007, Maria Teresa was appointed UNICEF Eminent Advocate for Children,[6] in which role she has visited Brazil (2007),[7] China (2008),[8] and Burundi (2009).

[9] She is a member of the Honorary Board of the International Paralympic Committee[10] and a patron of the Ligue Luxembourgeoise de Prévention et d’Action medico-sociales and SOS Villages d’Enfants Monde.

[5] Maria Teresa supports the UNESCO Breaking the Poverty Cycle of Women project in Bangladesh, India, Nepal and Pakistan.

As honorary president of her own foundation, Maria Teresa set up Projet de la Main Tendue after visiting the Bujumbura prison in 2009 in Burundi.

In October 2016, Maria Teresa accepted an invitation to join the international Council of Patrons of the Asian University for Women (AUW) in Chittagong, Bangladesh.

[16] In February 2023 it was reported by several Luxembourg based media outlets that the Grand Duchess had once again been accused of treating staff poorly during an outfit fitting in October 22.