Then I feel may be comprises wouldn't be the apt word.We can call it Unconditional.Where you do not expect anything in return and just do things for his good.To love someone whole heartedly is not easy, it takes a bigger part of you. You invest emotionally and became ready to move your world upside down.
She always did the same thing for him.She never expected anything in return.Even when they were not in good terms she always tried to ease his pain.She saw him in pain,in happiness,strong and even completely vulnerable.But she accepted him the way he is.He came in her life with lots of baggages; anger,frustration,heart ache,not even family members in proper talking terms and kids completly at different ends.She aligned everything. She put lives in everyone. She understood him and started loving him and looking see through; ignoring his taunts and anger.
But he loved her because of her goodness and I fear for only"Goodness". He never saw her weak, in anger, unnecessary frustration and not even vulnerable. Apart from her physical inability,he has never saw her with her weakness which I think she doesn't have.She was always strong,loving,caring and ethically correct.
So loving her wasn't a big task. It is wired that way in humans. But to accept him with all his baggages and still loving him is " Truly Unconditional".