Hello Tricia, this is a very hard position for you and your Mother to be in. You will both have a lot to weigh up.
Take your time to get fully informed. If you can, accompany your Mum to appointments. You will need to be her advocate.
I think, that until such time as you are presented with treatment options, there are currently no decisions to be made.
This is a nasty cancer and current treatments are brutal. Your Mothers age and general health will be a huge consideration.
Yours sounds like a typical family.
Tammy

Caregiver/advocate to Husband Kris age 59@ diagnosis
DX Dec '10 SCC BOT T4aN2bM0 HPV+ve.Cisplatin x3 35 IMRT.
PET 6/11 clear.
R) level 2-4 neck dissection 8/1/11 to remove residual node - necrotic with NED
Feb '12 Ca back.. 3/8/12 total glossectomy/laryngectomy/bilat neck dissection/partial pharyngectomy etc. clear margins. All nodes negative for disease. PEG in.
March 2017 - 5 years disease free. Woohoo!