Second the motion to have her case reviewed (aka second opinion) at a CCC if the biopsy comes back positive for cancer. They will have a weekly tumor board with number of disciplines represented (Surgeon, radiological oncologist, medical oncologist, dental oncologist, etc.,) and they will have likely seen more cancer in a year than the ENT has seen in a lifetime, plus he is only one guy and has one perspective.
If you learn nothing else from this or any other source about oral cancer, getting her case to a CCC is the single most important thing to learn!
Depending on what her situation shapes up to be, they may even just recommend that the ENT go ahead and do surgery or if something like radiation is recommended and there is a lot of travel involved (Can be seven weeks for the usual round of nuking), your sister may consider having that done closer to home -- Alternatively, many CCC's know of or operate low-cost housing for patient and caregiver near the facility).
CCC's are so designated by the National Cancer Institute and must meet the standards established by NCI. Here's a list from this Forum of CCC's by state -- There is one in Madison WI at UW:
http://www.oralcancerfoundation.org/resources/cancer_centers.htmI know it's too soon to tell and be specific, but some of the questions you asked can be difficult to search (BTW, search the forum by using the Search application button on the top tool bar).
I have had some chunks of my tongue cut out (aka partial glossectomy), followed by radiation, and once the effects of the radiation had mostly worn off, I was able to eat as usual although my taste buds and saliva mechanisms were damaged, so I had to carry water with me and drink a lot with meals.
I had more cancer and this time they took a substantial portion of my tongue, replacing it with tissue from my wrist to construct a 'free flap' new tongue -- Being sewed to the floor of my mouth, it didn't work as good as the original, so my eating changed but I was still able to eat with friends, although not talk as much (A bit of a hardship with me!).
Still more cancer involved total removal of my tongue (except about 5%, containing some taste buds) -- I am still recovering from that surgery, plus the front part of the new flap (this time from my thigh) and the front part of that didn't take (insufficient blood supply), so the jury is still out on how well I will be able to eat (currently getting my nourishment via liquid food through a feeding tube in stomach wall) -- I may have to make one of those $200 spoons discussed in another thread <grinz>.
Try searching "glossectomy spoon" for practice.
Some folks have had even more work done, but most here have needed far less. Since her ENT said it looked like an early cancer, her treatments may involve less and will most likely be more effective -- Early detection is an important key to fighting oral cancer.