Im new here. Mom has bc and now bone mets

I have learned more this past few days about cancer then I ever knew, but still dont know enough. Im not sure exactly what I need to know in order to assure my mom gets the best chances. Can you help me by telling me what to ask the dr?

She is 72. She was never sick before the cancer. Last May 2009 she had a masectomy but they said the margins were clear and thought it was gone. She went thru 4 chemo treatments and then collapsed one morning. When I took her in she was dehydrated and her white blood cells were at 500 (dr said he never heard of anyone with them that low before). While in the hospital she developed VRE. There was a serious infection found in her colon too and they pulled out about 1 foot of it. While she was in chemo she would have shortness of breath a lot but the dr did an xray and said nothing was wrong. She was hallucinating and stuff in there but wasnt on any drugs that would effect her mind. She had never shown any signs of forgetfulness or anything before this. She also developed pneumonia (2x) and a bunch of weird stuff in there. She was in ICU and rehab 118 days. She went on to learn to walk again (though always complained of back pain, shortness of breath, and numbness of toes). Her dr didnt do anything about her complaints and said they were nothing. She got 3 good quality of life months.

In the beginning of October she got sicker and sicker to the point I took her to the ER a few days ago. She is diagnosed with bone mets and 3 or 4 broken ribs and they cannot find the mass. They have run ct scan, bone scan, mri and an xray. They are going to do a colonoscopy. Her mind is going (not bad yet, but going), her feet are both numb now (it used to be her toes), she has pain often in her back but she hasnt asked for meds yet.
They have done blood transfusions because she got anemic, they gave her something to bring her calcium level down (it was 14 when she went in, now it is 9.2), they are giving her levaquin in an IV. They said they cannot find the "mass"

Thank you all for being here.