Breast cancer stage 2 prognosis?

[Slightly worried]

My mum (59 years of age, no prior health complaints, never smoked, drinks lightly, eats very healthily and has no history of cancer in her family) has just been diagnosed with stage 2 breast cancer. She's been told she needs a lumpectomy followed by 5 weeks of chemotherapy, that there's no chance of a masectomy and it's "eminantely curable" in the doctor's words. While I know it's difficult to say the least to give a prognosis over the web like this, given the facts outlined, my question is threeofold:
1) Is it likely to shorten her life at all?
2) Is it likely to recur?
3) Is it likely to massively change her quality of life in the every day practical sense, the implications of chemo and the like excluded?
Particularly appreciate honest opinions from survivors and those in the medical profession. Thanks for taking the time, really appreciate it.