If I were you, I'd look for something that would help in putting on muscle. The problem that many people have (specially women) is that they focus too much on cardio programs (i.e. doing spinning classes, jogging, and kick boxing) while neglecting something that will help them put on muscle.
The beauty of weightlifting for example, is that for each pound of muscle you put on, that pound will need to be fed and you will have a higher base level of calories that you can consume before you start putting on more weight. Also, you ramp up your metabolic rate and have positive effects on your hormones for fat loss and muscle retention if you workout properly.
You will also want to strengthen the muscles to help give them a better shape. Think about it this way, as a woman, you wouldn't want to have a flat rear end after doing so much cardio and stuff (think marathon runners), so doing squats and lunges will put some quality muscle back there giving it an attractive shape.
Another thing to remember is that women only have a SMALL fraction of the testosterone levels that a man has, so you don't have to worry about building muscle like a man. If it were that easy to add muscle I'd look like a gorilla. Moreover, muscle is many times more dense than fat (appox. 7 lbs. more) which means that you will barely notice an increase in 5 lbs. of muscle, but in the process of adding those 5 lbs. of muscle you could end up losing 7lbs of fat making a huge difference with just a 2 lbs weight loss overall.
Without knowing your body shape and other details I can accurately give you a good workout program, but I can try this and see how it does:
Day 1
Circuit 1
Cardio for 10 Minutes\t\tHIIT
Circuit 2
Powercleans\t\t\t4 X 10 reps
1 Minute Rest\t\t\t
Circuit 3
Dumbbell Squats\t\t\t3 x 10 reps
1 Minute Rest\t\t\t
Circuit 4
Dumbbell Deadlifts\t 3 x 10
No Rest\t\t\t\t
Leg Curls\t\t
1 Minute Rest 3 x 10
Day 2
Circuit 1
Cardio for 10 Minutes\t\tHIIT
Circuit 2
Squats\t\t\t\t_____\t_____\t_____\t_____
1 Minute Rest\t\t\t10\t10\t10\t10
Circuit 3
Dumbbell Presses\t\t\t_____\t_____\t_____
1 Minute Rest\t\t\t10\t10\t10
Circuit 4
Inclined Dumbbell Presses\t\t_____\t_____\t_____
No Rest\t\t\t\t10\t10\t10
Inclined Dumbbell Flies\t\t_____\t_____\t_____
1 Minute Rest\t\t\t10\t10\t10
Day 3
Circuit 1
Cardio for 10 Minutes\t\tHIIT
Circuit 2
Bicep Curls\t\t\t_____\t_____\t_____\t_____
1 Minute Rest\t\t\t10\t10\t10\t10
Circuit 3
Lunges\t\t\t\t_____\t_____\t_____
1 Minute Rest\t\t\t10\t10\t10
Circuit 4
Triceps Kickbacks\t\t _____\t_____\t_____
No Rest\t\t\t \t10\t10\t10
Triceps Pushdowns\t\t _____\t_____\t_____
1 Minute Rest\t\t\t10\t10\t10