prognosis for my mother - please help

I just received the following information from my mother.  She was treated for breast cancer in 2001 with no lymph node involvement.  She recently was experience stomach pain and went for a sonogram, (seeming unrelated transient intenstinal inflammation that went away).  During this time they discovered "small spots on her liver"  subsequent tests within the last few months have revealed the information below.  

She wont be seeing her doctor for a while and I know her doctor is the best person to answer these questions, if there even is an answer but I am just hoping to get a realistic idea of what we're dealing with (in terms of time).  Are we talking 6 months or 6 years.  I am getting married at the end of April and I'm just trying to wrap my head around what the worst case scenario is.

The PET scan revealed two large hypermetabolic foci in the liver, one in posterior left lobe (3.3 cm  with maximum SUV of 3.9) and one in superior right lobe (3.9 cm with a maximum SUV of 2.9) and in my left hip bone (a hypermetabolic destructive lesion in the left iliac bone along the sacroilliac joint with a maximum SUV of 8.8).   The biopsy revealed that the cancer is ER positive and Her-2 positive, although % not yet known.
The probable treatment plan involves hormone therapy with Femora (Letrozole) pills to suppress  growth of estrogen receptor (ER) positive cancer cells, a monthly infusion of Zometa (a bisphosphonate) to delay bone complications and participation in a National Cancer Institute trial of Avastin (bevacizumab), a drug that might halt progression by blocking blood flow to the tumors.  

Anything you could tell me about what to expect at her doctor's appointment or important questions to ask will be very helpful to me.

Thank you

[Cleveland Clinic]

Dear Fuzzdoodle:  The final treatment decision will be made based upon the final results of the HER2 assay as well as the other information you have presented and the doctors opinion as to the best approach.  Prognosis in this scenario is impossible to predict.  It all depends upon how your mother responds to treatment.  This problem is not curable but it is treatable and outcome depends upon how she does with treatment.  

[Fuzzdoodle]

Thank you for your response.   In the event that she doesn't respond well to the treatment, how quickly could something like this become debilitating.  How soon after beginning treatment will we know if it is having any positive effect?