Marrero's career in the hospitality industry began when she accepted a job to become part of the opening team of New York's Flatiron Lounge, led by cocktail savant Julie Reiner.
In 2008, Marrero moved to Elettaria in the West Village neighborhood of Manhattan, where she and fellow mixologist Brian Miller created their award-winning cocktail list.
"[citation needed] After winning awards at Rye House, Marrero and partner Jim Kearns created the cocktail program at the Astor Room in the Kaufman Astoria Studios.
In 2009, at perhaps the height of her on-bar career, Marrero was presented with the James Beard Foundation award as one of "America's Leading Female Mixologists."
In 2011 Marrero and Mix created "Speed Rack," a national cocktail competition for female bartenders that raises money for breast cancer charities.