What do you suggest if my mom has a grade 3 stage 2 her 2 breast cancer how deadly is this what is the chances of survival?

Many cured, not all: Stage 2 breast cancer is cancer which has spread to the lymph nodes of the armpit. After surgery, most patients benefit from adjuvant therapy. That is treatment given to prevent recurrence. Depending on details of case that may be hormonal therapy or chemotherapy. HER2 positive patients also benefit from Herceptin (trastuzumab) to prevent recurrence. Many, but alas not all, patients are cured.