[1] She attended the University of Barcelona, where she graduated with a doctorate in economics, having previously also studied commerce, philosophy, literature, and law.

[5] In 2009, Martínez Castells co-founded, and then chaired, the public health platform Dempeus per la Salut Pública.

In May 2015, Martínez Castells was ranked in the 32nd place on the party list of the Barcelona en Comú in the municipal elections.

[8] After the coalition Catalunya Sí que es Pot was formed, she was also highly placed on the resultant party list, and she was elected to the Parliament of Catalonia where she served until 2017.

[10] In the session of 7 September 2017 in which the Parliament was voting on the Law of juridical transition and foundation of the Republic, the deputies of Citizens and the People's Party of Catalonia left their seats in protest against the discussion, which, according to these parties, implied a violation of the Spanish Constitution and the Statute of Autonomy, and left Spanish and Catalan flags on their seats.