Hi and thank you for your question. She is going to check further to rule out breast cancer... but try not to worry too much, lymph nodes can enlarge for many reasons including inflammation, infection and even due to a pimple in a nearby area.
Per the Mayo Clinic the following are signs of breast cancer:
Signs and symptoms of breast cancer may include:
Breast cancer is much more commonly on ONE side, rather than both , so the fact that you have enlarged lymph nodes under both arm pits is less worrisome:-)