You need three things for weight loss: a clean diet, cardio, and weight training. Clean diet is THE most important for weight loss. If you need more information on that, let me know.
You should vary your cardio to keep your body guessing...run, bike, swim, elliptical, jumprope, etc...anything! The level of intensity should also vary. Some days you can only do 20 minutes of high intensity cardio and some days you can plug along for 45 minutes at a low to medium intensity.
Weights are very important too though. Do you lift any weights right now? Lifting weights will result in muscle gain (not too much though if you're female) which ultimately results in more calories burned.
By the way, what is a stone? I've seen it in books and on this board but I don't know how much it is. Congratulations on the weight loss though!