Another vote for diet and exercise. Mostly diet. If she isn't counting calories, she has to start now. Weight loss is about 95% diet and 5% exercise. Exercise is (of course) important, but walking 30 minutes a day works well along with a calorie-restricted diet. Over the past year, I dropped about 100 lbs. That involved a reduction to about 700-1,000 calories a day. The first month is awful, but then you get used to it and the pounds slip away. The reward that first month, however, is that you'll lose a huge amount of weight. Up to 20 lbs. is possible, so you get instant feedback and start feeling really good about what you're doing. People will notice and comment, so there's reinforcement there, too.
Diet is pretty simple. First, stop drinking calories. Switch to water, soda water, tea, and coffee. No diet sodas - they're just a stew of chemicals you don't need and they're more expensive than the alternatives. Next, fill up on bulky fruits and vegetables. Those are good for you, but the beauty is that they're bulky and make you feel full while having few calories. Keep at it and the weight comes off. I eat a maintenance diet on Saturdays and eat freely on national holidays and at family events. It works.
As for the friend aspect, she needs to get involved with hobbies/groups and hang out with co-workers. For example, the meet yesterday was awesome. I like all the equipment and listening, but going out to dinner with everyone was the best part.
She should also volunteer a charities and join groups. If she likes animals, have her volunteer at a shelter. She'll meet all sorts of people and will be thanked often for her help. There are many similar opportunities.
Just start doing that and the rest will take care of itself. She'll be fine.
