Hi Penny: There are VERY reliable tests that women can take to see if they carry the BRCA1 or BRCA2 genes, both of which carry a significantly increased risk for breast cancer. The tests can be quite expensive ($3000-$3500), and not necessarily covered by insurance, so that might be a consideration... But I would urge your daughters to speak to their GP about the test, and the possibility of them having it done. With the history of cancer in your family, it certainly seems like a reasonable thing to look into. Also, take a look at my post on taking the test, and some of the issues it can surface: http://www.healthcentral.com/breast-cancer/c/78/23994/brca-gene/1/ Good luck, Penny, to both you, your sister, and your daughters.