Emma, daughter of Ewings foe Harris Ryland initially seems as icily cold to the Ewings as her grandmother Judith. But Ann eventually connects with her, and Emma leaves the controlling Ryland family to live with the Ewings at Southfork where she quickly develops a fondness for both John Ross and Drew.
The Emma is appropriately tart and fiery, owing to the grapefruit flavor she shares with her grandmother and the habanero shrub, which represents her attraction to Drew. The bourbon is for her other potential love interest: John Ross. She shares the gin with her grandmother but it also represents England, where Emma learned to ride horses.
I made the grapefruit soda myself by carbonating fresh grapefruit juice in a siphon. But a commercial brand, such as Fresca, could also work.