Breast cancer lumpectomy-radiotherapy-chemo timeframe

My mum got her results, she has a tiny 16mm tumour in her right breast & not two as previously thought 

Surgeon said they had caught it early. 

All other blood tests and cat scans throughout her body are clear of cancer. 

He said at she has the aggressive fast growing cancer and has recommended the following : lumpectomy & lympnodes removed under right arm followed by radiotherapy followed by chemotherapy 

mum doesn't know what to expect, is the lumpectomy followed by radiotherapy followed by chemotherapy normal procedure?

does anyone have any experience of this treatment plan?

does anyone know or have experienced not losing your hair on head using this treatment plan?

how many sessions of radiotherapy & chemo is normal?

she goes into hospital Monday any help and advise will be much appreciated 

 

thank you