Cortina was born in Ariguaní in Magdalena, Colombia, and grew up in Plato.[3]
Her father played and fixed accordions, and she would sometimes play the ones he was repairing.[4]
Cortina began to play accordion at parties at the age of 10, with musicians like Eliseo Reyes and Modesto Barrios.[5] In 1980 Cortina's godfather took her to perform at a vallenato festival in Santa Marta. Her father first saw her play at a vallenato festival in Plato; he had entered her brother, but withdrew him when he saw Maribel perform.[5]
In 1993 Cortina formed Las Diosas del Vallenato with Patricia Teherán. The group released an album Con Aroma De Mujer in 1994, and were planning a US tour when Teherán died in January 1995.[4]
Following Teherán's death, Cortina recorded the albums Por Siempre y Para Siempre and Contra Viento y Marea with Baudilia Gutiérrez and Rosalba Chico. Las Diosas split in 1997 and since then Cortina has played with singers including Julio Gutiérrez, Rocío Rojas, Luchi Ortega, and Miriam Negrette.[4][6]
Cortina participated in the amateur accordionist competition of the Festival de la Leyenda Vallenata in 1985, 1986, and 1988, coming second each time.[4]
From 1989 she competed several times in the professional accordionist competition, and as of 2014 was the only woman to have done so.[7]
Cortina has publicly stated that she has not felt discriminated against at the festival because of her gender.[7]
In 2019 the festival split the accordion competition into separate men's and women's competitions, and Cortina lost in the final to Loraine Lara.[8][9]