Wow, I did NOT know that until this day. I assumed bone shape would always remain the same.
Edit: so hormone therapy alone can lead to her having wider hips, breasts, a slighter build, etc.?
From my understanding (in terms of the difference HRT makes at different steps), think about what's already happened, and what hasn't.
If you're a pre-teen going into puberty, and you switch your hormones from one sex to the other, you would then go through the puberty of that new sex. If you're going from male to female, you'll grow breasts, but you wouldn't suddenly grow, say, ovaries or a vagina, because those are things that don't grow at that point. If you're going female to male, your voice would deepen, and you'd grow facial hair (because, again, those are things that hit via puberty).
Then there's things that depend on when you start HRT. If you're born male, and take hormones before your voice deepens, then I think female hormones will stop that from happening. If you start HRT after your voice has broken, it won't magically reverse itself. If taken early enough, then I think bone structure can be altered, because bones are still growing. If you take hormones after your bones have stopped growing, they wouldn't be affected.
However, body shape does change due to fat distribution. Going from male to female, not only can you grow breasts, but fat distribution changes can do things like giving you more shapely hips/ass, soften your face, etc. Muscle mass will also reduce, so you'll end up looking smaller due to that.
Results also totally depend on your genetics. I know some transgirls who barely end up with an A-cup breast-wiseand then I have another friend who ended up with amazing C-cups. So that too can be a major differential in the results people end up with via HRT.