Sara and her family got it together pretty well after the loss of Anna, which shows that they were capable of being good parents, and have a mentally healthy family. If they could have been that kind of family from the beginning, things would have gone much better for all.
Hindsight is 20/20, so it easy to say afterwards, but I think the scene of the bone marrow transplant could have been handled much better. Did anyone tell Anna that it was going to hurt? She didn't need to understand the full medical details, but she was old enough to be informed about what it was going to be like for her. It may have taken a few more days, but I think her love for her sister would have brought her around in the end - voluntarily, which would have made a huge difference. And it would not have hurt any to treat Anna, Kate, and Jesse to a trip to Disneyland afterwards, to celebrate as a family. That's what Mastercard is for.
The sense of doing things together is what seems to have gotten lost in this family, and it took the death of Anna to snap them out of it. Being determined to save Kate is well and good, as long as it does not lead you down the path of ends justifying means. You still have to do things the right way, while having the determination to stick with it until you get what you need. I think if Sara had shown more respect and love to Anna, Anna would have been looking for more ways to help out, not trying get out of it.
Steve