Consultation related to Breast cancer.

My question is to an oncologist.My age is 30 years and the girl's age is 28.My question is related to my marriage proposal.I am very much confused to take decision beacuse the mother of the girl had expired due to breast cancer. The cancer had diagnosed at the age of 45 and after 5 years of treatment i.e. at the age of 50 her mother expired from breast cancer. As this breast cancer can be genetic disease also and on Google there are several article where it is written that the chances of breast cancer to a daughter is double then in the normal cases.I am working in IT sector and the girl is working in a bank.This informtion is just to brief you about the background. So sir/ma'am please suggest what to do in this case. (1).What are the chances of getting breast cancer in the girl (2).What are all the preventive measures that we need to take if I will go forward and accept this marriage proposal case.