I’ll add a few thoughts to the discussion,

The Superman pose (spinal overextension) is not recommended for someone with severe osteoporosis, so double check on that.

HRT can help slow bone loss, but with a lowest T-score of −3.5, an anabolic-first approach makes more sense than an HRT → PTH or HRT → HRT + PTH sequence. Between the anabolic options, I’d lean toward a PTH analog as well. A TBS showing deteriorated microarchitecture would reinforce that choice.