I dunno what to say about this, cause I don't want to worsen it for you but. Things like those, they're not in our control. It's not our own fault. You don't have to blame yourself or beat yourself up about this because you didn't make it happen. And sometimes, with these problems, comes the downside of one not being able to directly help them. It hurts, but in those cases the most we can do is be by their side, take care of them best you can, pray for their wellness, and let them know you absolutely love them no matter what. Please, for what you can do, let her know you love and care for her with your heart.
I hope this was able to help a bit. If not, I apologize.