Oh dear. I hope someone can come along with good advice from having been in your position.
However I'm sorry, but from the other POV I think you've said it yourself - the ball's entirely in her court and if you care about her, you can't keep focusing on wanting your fun buddy back.
I'm currently watching 2 friends at work have happy healthy 3 month+ pregnancies while we're onto our 4th early mc.
It's like being stabbed sometimes, and it has fundamentally changed our relationships - I just can't be as close to one of them in particular. It's totally irrational and I hope I've stayed professional, certainly haven't burst into tears in front of them or been mean or anything, but I am having to distance myself as I just can't see them in the same way anymore and I hate who they turn me into.
I can't stop wanting to cry sometimes, or have to wear this fake smile to stop them sending what I'm thinking. When they moan about pregnancy, it's all I can do to sympathise and then walk away without stabbing someone. When they don't talk about pregnancy, I wonder if they're pitying me or something. I can still see their bumps which they hold/stroke without thinking. They are a constant reminder of a primal need I cannot meet.
Having said this like the masochist I am in a misguided effort to be supportive at first I offered any help I could too. I've lent pregnancy books to one and end up being the other's sounding board about miscarriage fears. It's not good.
My best advice would be to back off, stop texting, let her process things, and if possible, be sensitive about things you post on FB etc.
I think you also have to understand that the relationship you had has changed forever. You have what she wants, you'll always be ahead of her, and even if she gets pregnant (and it's an "if" not a "when", please don't assume it will happen for her), it's not going to instantly heal things.
Gosh sorry I've gone on a bit there. Hope it helps and isn't too self pitying...
and I do hope you can both heal in the end.