Hi Annie,
I can imagine how anxious you are - I can remember when it was all first happening with Mum, were in a state of absolute shock. Mum had radical treatment too - mastectomy, total axillary lymph node clearance and is now going through 6 rounds of fairly toxic chemo (not sure about radio at this stage as it had only spread to 1 lymph node). You just have to think that you are attacking this with everything in your power - if it's aggressive, you'll be aggressive back. If they do as much as they can at the beginning when it's contained, there is less chance of it recurring - hard in the short term, better in the long term.
Mum has also been told that she is eligible for the genetic testing because of the type of cancer (triple negative) and because she is under 50. She will be doing that next year after her chemo has finished in January. Her cousin also has breast cancer but not the same type as Mum's and it was on her Dad's side, so not sure of the genetic link there. I have heard that there is a definite link between breast/ovarian/bowel cancer so if there is any history of that in your family, you might want to chase it up. Can be hard without any family documents handy! Good luck with it all, warm wishes, Sarah.