The four weeks of metacam are realistic.
My hub broke a rib last autumn in a fall. It is a bone that cannot be splinted or bandaged (because of the need to breathe) and that needs healing on its own, as long as it is not poking into the lungs. He wouldn't even be seen by a doctor. Hub was in pain for about 5-6 weeks while it was healing on its own - it was a thicker bone but the leg is weight bearing so there is a bit of a trade off.
It does however sound like the bone knitting process is well underway with your little one. If your girl is able to walk and run without any major limp or wobble, it also means that the leg is healing straight and that there won't be any permanent pain. She is also young so the healing process will be a lot faster.
I hope that helps you? My elderly mum - who also has osteoporosis - is currently in hospital with two broken leg bones (in different places) after a bad fall, one of them a more complicated break, so she needed a couple of full ops last week just a few days apart. She is looking at a much longer recovery.