Mariana studied recorder, singing and keyboard at the Portuguese National Music Conservatoire in her native city of Lisbon. She was a founding member of this school’'s early music group Turba Conservatoriense, and was part of the National Conservatoire Baroque Orchestra. She was a member of the Peregrinação Choir at the same school, with which she recorded an album in 2008. She furthered her recorder studies at the Castelo Branco Polytechnic Institute, earning her Master of Music. She also holds a Bachelor of Musicology by the Lisbon Nova University.

She has performed numerous concerts around Portugal, both as a soloist and as part of a group, including a concert at the Belem Cultural Centre in a concert transmitted live by Antena 2 and later broadcast by BBC 3. Mariana has sung in several chamber, symphonic and operatic choirs, and in 2002 was invited to become a member of the Lisbon Chamber Choir with which she recorded 5 albums. Since her move to the UK she has joined the London Philharmonic Choir and continues working as a soloist. Parallel to her life as a performer, she has dedicated herself to teaching, having taught recorder, instrumental ensemble and choir at schools such as the Caldas da Rainha Conservatoire and the Portuguese National Music Conservatoire.