All women are at high risk?
Yes being a woman increases the life time risk of development of breast cancer. Some are at higher risk then the others.

What can a woman do?
Self-education is the key. Educate your self as much as possible about the problem. Enroll in an early detection program.  Ask your doctor. Check yourself to see if you find a hard or a firm lump in the breast. Hard is hard like your forehead. Firm is like the tip of your nose. Soft lumps are usually benign. Check for discharge from the nipple. If you have a doubt get your doctor to check it. Get a mammogram. Mammogram is a specialized x-ray of the breast that can show breast cancer early when it is very small and before any one can feel it. Get an ultrasound of the breast. Do this at least once a year.