@x2boys
Most patients who are ventilated have a breathing tube passed along their natural airway that is through their nose or mouth and down their throat. They have to be sedated because without sedation, where the tube passes the back of the mouth it would trigger gagging and coughing reflexes, which would be painful, frightening and would most likely result in the tube becoming dislodged.
Also, if somebody has (even partially) working breathing muscles and reflexes, then paralysing and sedating them also allows the machine to completely control breathing, instead of fighting the patients natural breathing responses. Or it may allow the patients own breathing systems to rest. Complete outside control over breathing might be helpful or absolutely necessary for survival depending on why the patient needs to be ventilated. (In some situations paralysis and sedation is "lighter" to allow the patients own breathing to take over more - particularly if they are getting ready to come off the ventilator).
However patients who are long term ventilated have a surgery to make a hole in the front of their neck, through which the breathing tube passes. The hole is called tracheostomy. This bypasses the coughing and gagging reflexes so sedation isn't necessary, allowing patients to be ventilated awake. You wouldn't put in a tracheostomy for everyone though as it's potentially dangerous surgery that has complications, has to be reversed and leaves a scar etc and for other reasons (eg above) it may be necessary or beneficial to sedate and/or paralyse them in any case.
In this case, the patients muscles are so damaged from her disease that they contribute nothing to her breathing so she effectively is already paralysed and that's why she needs ventilation in the first place.