Cool! In my experience, the first year she really can't go wrong lifting, no matter how she goes about it. I started with more of a Starting Strength idea doing 5x5 sets to build strength on my big lifts - squats, RDLs, Trap Bar DLs, Bench Press, and Pullups. I still don't have a pretty set of 5x5 pullups but that's another story! Then I did more of a body building type of deal for accessories with more like 3 or 4 sets of 8. I have progressed like crazy!
She's got the cardio in place already. Fitday.com might be helpful in keeping track of her diet. If she's been doing that much cardio for several years but is still 20 pounds heavier than she wants to be, then the diet may be key here. Maybe not as clean as she thinks.
And about getting bulky, I ate to gain a bit and put on 10 pounds over the first year. I've since lost bit. Anyway, very little changed in terms of my measurements. I mostly got more dense. My clothes all still fit, but I do look a bit more curvy. You don't see a bunch of visible muscle unless I'm all pumped up and flexing. If she starts lifting but is eating on a deficit to try to cut fat, she absolutely WON'T bulk up. No worries. She can't spot reduce her legs, but they will look more shapely and the added muscle on her back and shoulders will balance it and will also help her burn some of the chub off. I pretty much stopped with the cardio the first year since my goal was to try to put on and keep muscle.
I mentioned this in another thread so I'm starting to feel like a paid advertisement, but Jamie Eason has a Twelve Week Training Plan at a certain competitor's website that will remain unnamed. Google Jamie Eason Livefit Twelve-Week Trainer. That's where I would start if I were your sis. It starts with a 4 day per week lifting schedule, and more of a BBing style, but it also tells you exactly what to do and what to eat everyday. I think it's a perfect place to get started, particularly since her goals are more aesthetics and trying to up her metabolism a bit rather than strength.
Keep us posted on her progress. Before and after pics fo'sho'.