Diagnosis is hard, it changes how you see you self and you are left with what seems like a death sentence... Life long meds, it will never get better.
Some ideas:
Give her permission to feel hurt, angry, upset, let down etc but really gently help her try to get past that (probably a counsellor would be better for this).
Some days can be really hard - unable to get out of bed etc, but also BP can easily become an excuse.... it really requires judgement, you will sometimes get it wrong, but keep on trying.
Expectations, they can cause stress, but they also give hope that someone thinks that you have value and that you have a future. My husbands expectations of me are one of the things that keep me going.