A question about a recipe: Boozy Watermelon Rosemary Lemonade

I gave up most forms of spirits (including martinis) years ago but on those rare occasions when I would like something such as a French 75 I'll enjoy it with Hendrick's if only for the complexity of flavors. But it is expensive.

Gin derives its flavor from juniper berries; Hendricks' other notes are from infusion of cucumber and rose petals, which I think would be lovely with rosemary.