If she's a once in a while drinker, get the pre-mixed Long Island Ice Tea and be done with it. Add a shot of cheap *** rum and two shots of Sprite if you want to jazz it up a little.
Since the ladies in my life are serious drinkers, I mix up what I call Hellraisers. A whole pitcher consists of a pint of PGA, a pint of pineapple juice, a pint of cranberry juice (the 100%, no sugar added), and a split of Spumante (use club soda if you want to cut the sweetness down). If one of them says it's still sweet, cut theirs with vodka. Of course she'll be on her *** after the second one, but next time don't say it's too sweet.