Re: Why won't my legs tone up?
Remember that "spot reduction" is not effective in any practical sense. Exercising muscles does not preferentially reduce nearby fat. Try to do a balanced workout leading to fat loss and/or muscle gain. Note that accidentally "bulking up" is rarely a problem for men (actually a lot of men try to "bulk up" but don't) and even less likely for women.
A balanced workout will include chest (pushups, dips, bench press), back (pullups, rows), and core (crunches and such) as well as legs (squats, etc.). For greater strength gains, try heavier weights (for which you can do 8-12 reps at a time, increasing weight when doing 12 reps is easy). If you are doing cardio in the gym, you may want to consider full body cardio like rowing or swimming if available.