Lázaro was one of eight siblings born in San Juan, Puerto Rico and raised in the Miramar neighborhood of the city.
After high school, she was accepted to the University of Puerto Rico where she earned her Bachelor of Science degree with a concentration in education.
In 1987, Tony Croatto, a popular Puerto Rican folksinger, discovered one of her children poems and converted it into a musical hit.
Her poem "Mi Flamboyan amarillo", or "My Yellow Royal Poinciana", originally published in 1996 by Ediciones Huracan, which issued two more editions by 2001, was reissued in 2005 by Lectorum Publications, a subsidiary of Scholastic, Inc.[2] She has also written poems that introduce children to Federico García Lorca, Pablo Neruda, Miguel de Cervantes' Don Quixote and other mainstays of Hispanic culture, as well as "Ya llegan los Reyes Magos!
Her poem "Ya Llegaron los Reyes Magos" received a recognition from the Pen Club of Puerto Rico and in 2002, the Ponce Chamber of Commerce honored her with an "Educator of the Year" award.