Please please forgive me if this seems so horribly insensitive, but I genuinely feel this is something you should put out of your mind. By the time your baby reaches 37 - even 27, the technology and surveillance will have developed even further, just look at how different the chemotherapy experience is now after 20 years, and how far scanning technology has come.
Because of her family history she WILL know how to self-examine, she WILL get scans, it WILL be detected early, and she WILL have far better treatment than we're getting. Her chances if in the unfortunate case it has been passed on are so good.
This is also a matter of stress becoming an enemy. It is something that could tear you apart if you let it and make everything so much worse for yourself. Stressing over problems that may not even exist, which if they did you could not change, is not going to achieve anything.
Control the things you can control. When she's 18 ask her if she'd like to be genetically tested. If it's positive, you'll know to be on higher alert. It's the best you can do. And it is NOT your fault.
Focus on yourself, your treatment, your coping. That is the best possible thing you can do for her right now.