In reply to Andrew Holden:
It might be possible to have this listed as an exclusion to a normal policy, ie she will be covered for any accidents that isn’t related to her Osteoporosis. I have multiple orthopaedic problems including recurrent dislocation, arthritis and am waiting for a couple of op.s to fix these. By shopping around and speaking to the BMC underwriters, I was able to get cover for off piste ski touring so long as any accidents didn’t affect my hands, ankle and left shoulder. Not much use perhaps but at least I get to go skiing.
Good luck with all this, keep trying. If it really doesn’t work out, there other ways to love being in the mountains that are safer but still fulfilling. Best wishes.