She was married in Vienna, 13 October 1945, to Dr. Nicolaas van Uden (Venlo, 5 March 1921 – Lisbon, 5 February 1991) who was Dutch and who became a naturalized Portuguese citizen in 1975.

The Portuguese President of the Council of Ministers, António de Oliveira Salazar intervened with the Germans, claiming that Princess Maria Adelaide was a national heritage[citation needed].

But when Dr. Nicolaas van Uden arrived in Portugal his qualifications were not recognised as equivalent to the Portuguese ones, and therefore he could not practice medicine[citation needed].

Princess Maria Adelaide began working as a social assistant in some initiatives, because that area of Trafaria in Monte da Caparica, was very poor.

She developed an intensive career, especially in the area whereby newborn poor or orphaned children were collected and then taken to the D. Nunes Alvares Pereira Foundation, of which she was President.