Hi Sandra: Congrats to your mother on her success with Fosamax, that's incredible.
In regards to your treatment, I would double check with your GYN, to be sure you can get Fosamax when your pre-meno. There seems to be a gray area around this topic, so I couldn't say for sure what the medical thinking is on this, but if you read about Fosamax, it does say that it's FDA approved for those who are post meno.
I have heard of Drs that will prescribe this anyway, but the main concern is your ability to become pregnant, and what if any effect this drug *may* have on unborn children or children that nurse from the mother, if you should become pregnant while taking a bisphosphonate. The Dr you are seeing should be a good resource for answering this question.
One other concern might be the half-life, of the drug, (time drug remains in the body) for those who could become pregnant. Merck claims that the drug remains in a measurable state in a patients urine for ten or more years, so this is another reason why pre meno patients are screened very carefully. Since no studies have been done on the effects of these drugs and children it's impossible for me to say what may be a feasible treatment for you.
Only you can make this decision, so if you need to find some other treatment that is approved for pre meno patients here's a link on Fosteum that is available.
Good luck and let us know what you find out on this topic.