She may have an ill family member (mother? spouse?) I don't think she is sick herself because I don't think this would happen so quickly--most T's try to prepare patients if possible.

So sorry to read this, it must be a shock. It's easy to assume burnout, but it may not be the reason. Maybe on some level you feel like you helped burn her out ---most likely not true of course!! Sorry, i'm playing amateur T i guess.