I am so terribly sorry to hear this. Having lost 2 babies before I carried one to term I know her devastation & I lost another baby between my son & daughter. I totally understand her feeling of loss & heartbreak. It won't make her feel better but my dr told me that if every woman got pregnant enough times, that eventually every woman would suffer a miscarriage at some point. He said unfortunately for some womem, their miscarriages happen early on in their child bearing. And although I had 3 miscarriages, I also gave birth to 4 very healthy babies.
I feel so sorry for her & for you. You've both suffered a loss & now you have to watch your daughter grieve. I wish there was something I could do to help both of you.