I think the thing with mc is that your feelings are so personal to you, that the chances of anyone saying the "right thing" are negligible. So, for me, having the mw say "maybe you're one of those women who can only carry girls" made me want to smack her in the face, when a friend I know found that really comforting. And my sister whose theory is that "your body will carry a baby when its the right time, and lets face it, there's so much upheaval in your life now that this isn't the right time" really annoyed me.
I think even if you've had a mc it doesn't always mean you'll get it right, but at least you're more likely to stick with the only safe thing to say which is "I'm so sorry for your loss". 
So Guff, I also think you should give your friend a pass on this - I think she was trying to be supportive and say that she thinks you are strong and brave (and remind you that you are stronger than you think).
Remember ladies, we are all strong, resiliant and AMAZING women who have managed to survive one of life's bigger setbacks and, even more amazingly, voluntarily put ourselves through it again, putting on brave faces and never letting the world see that we're all dying a little inside because we're so terrified.