Very sorry to hear that your mother is suffering from metastatic breast cancer
and she is having terrible pain due to the bone metastasis
Unfortunately stage 4 breast cancer is not curable and the only treatment one can offer is palliative. But this does not mean that things have ended. Palliative treatment has also improved over the last few years and patients benefit from this treatment. Referral to a palliative care
consultant in your case could be to advise you regarding the newer modalities of pain relief.
Hope I have answered your questions and your mother finds better pain relief after consulting the palliative care physician.