Lucille Ball and Desi Arnaz's daughter Lucie Arnaz posted a sweet birthday message to her brother, Desi Arnaz Jr.

Arnaz wished her “beautiful baby brother” a happy birthday via Instagram Lucille Ball and Desi Arnaz’s daughter celebrated her younger brother ... Arnaz IV,” Lucie Arnaz, 73, wrote ...

Lucille Ball and Desi Arnaz’s daughter celebrated her younger brother’s birthday this ... My beautiful baby brother, Desiderio Alberto Arnaz IV,” Lucie Arnaz, 73, wrote in the Monday ...

Lucille Ball and Desi Arnaz; Lucie Arnaz and Desi Arnaz Jr. as children in the 1950s ...