Use a cloth dampened with cold water or filled with ice. This helps reduce pain and swelling. If the injury is on an arm or leg, elevate it. Apply 0.5 or 1 percent hydrocortisone cream, calamine lotion or a baking soda paste to the bite or sting several times daily until your symptoms go away.
She is incorrect in saying that she will not get breast cancer with 100% certainty. Although, since her BRCA1 and BRCA2 alleles were found to have no mutations signalling breast cancer, this means that there might be a very small chance that she could still develop breast cancer.
Even though it is highly unlikely that she will develop breast cancer, there is still a very small chance that it can occur.