Breast cancer with leptomeningeal metast

Patient was diagnosed with breast cancer in sept 2020 underwent mastectomy, chemo and radiation and then pet scan reports were clear. but soon after started to experience severe pain in lower back and back side of legs. After several tests and finally the lumbar puncture she has been now diagnosed with a metastasis disease and hence again underwent radiation for a week and now chemo ongoing. I googled about this and it shows its a stage 4 cancer and mostly its not curable. However the oncologist we are right now consulting who's practicing in kokilaben hospital Mumbai told my father that it's nothing major and her body will respond well to treatment and she'll recover so nothing to worry. But today after actually googling and getting some info on her disease i'm worried who to trust and is it true that my mother has only 3-6 months more? I just need a clarity and a second opinion from an actual doctor assuring my mother's life.