 Alejandra Gollás, like her character Mimí, is a former child star.  She starred in "Quinceañera", the soap opera that is briefly shown  in the movie, and her mother in that role was Julieta Egurrola, that  plays her mother in Efectos Secundarios too. Also, she was the title  character in the musical Annie; hence, the singing of "Tomorrow" in  the car scene with mom.