Jackie Guerra wanted the part of Selena's sister, Suzette, so badly that she lied at her audition, saying that she was an experienced drummer, when in fact she had never played the drums. After her inexperience was finally revealed, Selena's real sister Suzette gave her private lessons.
When Jennifer Lopez signed on to play Selena, she expected to be providing her own vocals. However, it was felt that since the movie would be released so soon after Selena's death, her fans would not approve of hearing any voice other than hers. So, Lopez was coached to lip-sync instead of being provided the vocal coaching she expected, although she did sing the intro to "Como La Flor" in the Monterrey concert scene.
In real life, Selena, who was from Texas, had a mild but obvious southern accent (and can sometimes be spoken fairly strong with some words). Jennifer Lopez, who is from New York, (with help from the family) portrayed this accent in the small subtle ways you would hear from Selena in her interviews.
Among the actresses considered to play the title role were Leticia Miller, an unknown who bore a striking resemblance to Selena, and Bibi Gaytán, a Mexican soap opera actress. Coincidentally, Selena Quintanilla-Perez had guest starred on a soap opera Gaytán starred in, called "Dos mujeres, un camino."
According to an interview on ET with Abraham Quintanilla Jr. and Suzette Quintanilla, Abraham confessed that the scene where Marcella teaches Selena the washing machine didn't actually happen, but it is true that they would all sit on the beach by the ocean together as a family.
The real Abraham Quintanilla (Selena's father (who served as executive producer)), wanted the scene of Selena and Chris Perez getting married out of the film because he didn't want Selena's younger fans to get the wrong idea about marriage. He was later convinced by director Gregory Nava.
Panchito Gómez played a young Abraham Quintanilla while actor Edward James Olmos played the older version. In the movie American Me, Panchito played the character Montoya Santana as a young version and Edward James Olmos played Montoya Santana as the older version.
The trivia item below may give away important plot points.
Selena's death occurred five days after that of Eric "Eazy-E" Wright, who was the subject of another music biopic - "Straight Outta Compton" (2015). Eazy-E died 26 MAR 1995; Selena was killed 31 MAR 1995.