Gallego began her career in 2004 producing Wandering Shadows, a film by her then husband Ciro Guerra.
In 2009 while producing another Guerra film The Wind Journeys the pair befriended members of the Wayuu community.
They spent the following ten years researching material for their film Birds of Passage which follows a Wayuu family as they abandon traditions and fall into the drug trade.
Gallego made her directorial debut with the film which she codirected with Guerra.
[1][2] It was selected as the Colombian entry for the Best Foreign Language Film at the 91st Academy Awards,[3][4] making the December shortlist.