How to Make a SkinnyGirl Margarita. If you're ordering a Skinny Girl at a bar, you can have it on the rocks, but replace the Triple Sec. Here's the Skinnygirl Margarita recipe. Serve this site by trying to find the Skinny Girl margarita everything ourselves vs buying the bottle. Are Skinnygirl Drinks Better for You than Regular Cocktails She started off by creating the Skinnygirl Margarita as a lower-calorie option 5 Skinny Cocktail.