Are Kettlebells OK For A 57 Year Old Mom?

My mother is 57 years old. She was just diagnosed with Type 2 diabetes. She needs to lose a lot of weight (approximately 20-30 lbs to get her blood sugar to drop, and 60 lbs to be really fit). She has a history of high blood pressure and high cholesterol, but seems to have both decently under control with medication and exercise. She has a bad knee that will likely need replacement within the next five years. Her latest bone-density test showed that she’s starting to show signs of increasing risk for developing osteoporosis. She has a pretty good diet but is now ready to make needed changes in caloric intake and consumption of healthy, natural food.

She’s been cleared by her physician to exercise. She owns an elliptical machine that she uses for long-slow workouts a few days a week, but it hasn’t really done much for her.

I’ve had great results in my own training program using kettlebells and bodyweight-only exercises for timed intervals (i.e. AOS Providence, Whitley Power Circuit). I’m a true believer in interval training for cardio and fat loss.

I know my mom could lose a lot of weight using kettlebells and interval training instead of her long-slow hamster workouts. She’s a naturally muscular lady who would get a serious burn from doing ballistics. But I’m concerned about 1) her knee, 2) her getting her heart rate up too much, too fast and 3)the possible bone injury from the inevitably clumsy process of learning how to properly clean the kettleball. But remember, she IS cleared to exercise.

Can you please share your thoughts about whether or not my concerns are founded, considering her profile? Also, if you think she’s still a candidate for KB training, can you recommend an RKC in the New York City area who has experience working with clients her age and fitness level (not to mention someone who could critique my form on key drills)? Also, preferably someone who’s well-versed in BW exercises?