A 56-year-old female client has discovered a new breast lump. The practical nurse (PN) recognizes that this client's greatest risk for a diagnosis of breast cancer is related to which factor?

She is postmenopausal and has been using herbal estrogen replacement therapy for four years.

There is a history of fibrocystic breast changes and she describes the lump as painful.

The client is of normal weight and height and has had three children before age 28.

She describes the lump as non-tender and says her mother died of breast cancer.