Respiratory Problem (?) Ventilator Induced?

My sister walked into er and was diagnosed with menningitis and admitted to local hospital. She was on a regular floor for 8 days given antibiotics then she was dx with pneumonia. She coded and was put on a respirator and has been on it for over a month. She is kept sedated to the point that she does not move at all. When she was trying to breathe on her own and the machine went off, they further sedated her with versed, plus a continuous drip of versed. The menningitis was long taken care of and the lungs cleared of the pneumonia. When she was on the floor due to an error on someones part she had received 3 blood thinners at once lovenex, heparin plus coumadin. In the icu she had blood in her catheter bag for 2 weeks, and they gave her 5 units of whole blood plus plasma. Every time they were asked by the family about weaning her from the vent we were told that to be weaned off they had to lesson the sedation, and they could not do that while she was on the vent. 2 days ago they put a trach in and she now has a temp of 104*. Today the doctor told her daughter that her lungs had gotten hard and she was nearing the end, and they must make a decision whether to have them code her or not, suggesting that they should say not. Something seems terribly wrong with this picture, she walked into the hospital 6 weeks ago, she is not terinally ill...What is the problem here? How much damage can being on a vent cause? What do you think about his situation...Help me understand what has happened here. I don't want my sisiter to die. Thank you, please answer fast.