MDS is diverse and there is a lot of (mis)information out there. One of the best places I've found to get information on MDS is the Leukemia and Lymphoma Society page:
http://www.lls.org/#/diseaseinformation/myelodysplasticsyndromes/The disease can take many forms, some of which can be chronic for years to decades, requiring not much more than regular blood transfusions- maybe weekly, maybe every few weeks. That is a PITA because it involves many hours at the hospital for type and cross then transfusion, but other than that, these forms are not so bad.
Some mildly more serious forms respond well to drugs with relatively few side effects like Vidaza or Revlamid (though these drugs can be hugely expensive, so insurance is an issue here). These can also be kept under control, or even go into remission, for many years.
Some forms of MDS can be very aggressive, and can quickly progress to Acute Myeloid Leukemia, a form of leukemia notoriously resistant to chemo, leaving a bone marrow transplant as pretty much the only possible form of treatment, and that is quite radical and risky.
There is a very broad range. Her hematologist is the person who can provide more information about what her prognosis is; hopefully your friend is having frank conversations with her hematologist.
Wishing both you and your friend strength in this.
