Mercy turned 10 the day before.
Madonna has been dealing with negative feedback over late start times at her concerts on this leg of the tour, and in February will square off in court with ex Guy Ritchie over custody of her son Rocco.
Ahead of her Miami show, which was attended by the likes of Gloria & Emilio Estefan and Rosie O'Donnell, the superstar had taken to Instagram to post a note she had received from fans expressing their support. Her caption for the heartfelt letter was, "Thanks soooooo much for this! It means a lot to me! One word of kindness it can save me!" — a quote from her song "Joan of Arc."
Perhaps also hinting at her feelings regarding personal matters, Madonna surprised the audience with an unscheduled performance of "Don't Cry for Me Argentina," the signature tune from "Evita," the movie of which Madonna starred in 20 years ago. "I've been dying to do that song for the entire tour, and that's the first time I've done it." She referred to Eva "Evita" Perón as a "woman of power, a woman who was controversial… Damn it, Eva Perón was a rebel heart!