Here are the common themes on a variety of sites like NIH, National Osteoporosis Foundation, WebMD, Harvard Health:

It is difficult, but possible to improve bone strength, easier to stop loss.

The best non-drug treatments for slowing/stopping progress of osteoporosis are:
- Good diet with adequate protein (huge issue for older women, who tend to consume too little).
- Adequate levels of Calcium, Magnesiun, Vitamin K, Vitamin D3 & Zinc.
- Weight bearing exercise (walking, power walking, weight-training, stair climbing.) Swimming and biking may be good for cardio, but not as good at promoting bone strength.
- Avoid excess caffeine & alcohol which may promote bone loss (ie more than 4 cups of coffee a day.
- Stop smoking.

Alternative therapies are not scientifically proven to work, or may have side effects and should be discussed with your doctors, these include: red clover, soy, black cohosh, and other herbal supplements.

Finally, in addition to the traditional medications like Fosamax, there are now some biologics available which my be appropriate and less difficult to tolerate.
Sue