Mafalda

A nickname for Mafalda would be Mafia.

Also Galician: http://www.ige.eu/igebdt/esq.jsp?idioma=gl&ruta=onomast/nomes.jsp
https://gl.wikipedia.org/wiki/Lista_de_nomes_femininos_en_galego#I

Also Catalan: http://www.idescat.cat/noms/?q=Mafalda&lang=en
And Spanish: http://www.ine.es/tnombres/formGeneralresult.do?vista=3.

In the Harry Potter books by J. K. Rowling, there are two characters with the name Mafalda, one of which didn't end up being in the stories. The one that was in the stories was Mafalda Hopkirk, an assistant at the Ministry of Magic's Improper Use of Magic Office who issued warnings to those who used magic in front of non-magical people. The absent character was Mafalda Weasley, a cousin to Ron Weasley who would have been in Slytherin and been a Death Eater informant for the main trio, who eventually fell out of the story.

I know a woman named Mafalda in New Brunswick, Canada. She is 96 years old and told me her father chose the name because he had heard it and liked it. She said it was Italian but there were no Italian connections in her family.

Mafalda, an historical Portuguese name (that of our first Queen), was revived in Portugal in the 60's and 70's largely due to the popularity of the Argentinian comic strip 'Mafalda', by Quino. Nowadays it's rather common among the younger generations.