I have not been able to uncover much about Valerie Munarriz except that she is an Argentine tango & milonga singer who records on the Le Chant du Monde label. I will, of course, add more information pending some research.
Chante Jorge Luis Borges -- (1996/2001). An album of tangos and milongas with lyrics adapted from Borges' poetry.
AMG Card -- The All-Music Guide has a very sketchy card for Munarriz.
Le Chant du Monde -- the homepage for this world music label; curiously absent of any material regarduing Munarriz.