Ankurtg: So sorry to hear about Mom! I would recommend if possible that you get a third opinion if possible from somewhere like Memorial Sloan Kettering https://www.mskcc.org/news/what-to-know-about-getting-second-opinion-after-cancer-diagnosis
and/or UCLA........https://www.uclahealth.org/international-services/become-patient/telemedicine/second-opinion-consults
These days it is a MUST.
I wish you the best
Rick