SUBREDDIT: r/relationships
TITLE: I [33M] just started dating a woman [32F] whose child went missing 9 years ago. How can I support her?
POST: I met "Carol" through mutual friends about a year ago, but we only started seeing each other about a month ago. I already care about her very deeply. I learned a while ago from our friends that Carol had her first (and only) child when she was 18. The little girl went missing when she was six. Obviously, this has destroyed Carol. She does talk about her daughter sometimes, and I know she carries her photo in her wallet, but there is a constant sorrow that hangs over her. Even when we're having fun, I can see that she's feeling sadness at the same time. We've never had a detailed conversation about her daughter but she knows that I know the story. I'm always afraid to bring it up or say something about it that might hurt her. 

I want to be there for her, and I want her to know that even though this terrible thing happened to her, I'm going to do my best to make her happy. I know we're very early in the relationship but I can already see myself spending the rest of my life with her. 

Does anyone have experience with something similar? Does anyone have advice for how I can support Carol?
TL;DR: 
My GF of one month has a child who went missing nine years ago. She is recovering, but still (obviously) enormously affected by this. How can I express my support?