Rosita has a PhD in Biochemistry and Engineering as well as an online certification in Astrology.
Rosita works as a bartender at Shorty's and collaborated with Doc Holliday and Jeremy Chetri to help create a serum for Xavier Dolls. At some point, Rosita and Doc develop a sexual relationship (first seen in Whiskey Lullaby) and continue the relationship even though Doc might have gotten Wynonna Earp pregnant. Doc encourages Rosita to bond with the Earp sisters, so she decides to throw a baby shower with Waverly Earp for Wynonna. In the episode Forever Mine Nevermind, Waverly learns that she's actually a revenant and helps keep Rosie's secret from Wynonna. It's unknown if Doc knows her secret.