If there was another thing she would take great care of other than herself, her family, and her trident, it would be him.
After a number of battles, weapons tended to become dull and be rendered ineffective to use. This was why she would examine and polish her trident from time to time, to make sure it was in good shape anytime she used it.
Like weapons, he also needed to be taken care of.
Despite his efforts to hide his weariness, she was able to see through his pretense whenever they met. If he was in pain from wounds inflicted on his body, she would heal him. If he needed to unwind, she would soothe him. If he needed her, she would be there for him.
It became a routine, like taking care of her trident, to make sure he was at his best at all time.
Why would she spend her time on him? Why would she waste her energy to heal his wounds which could heal by themselves?
For her, time spent with him was worth far more than time spent on her own. Between having time to spend alone for a month and being able to spend time with him for just one day, she would choose the latter without a second thought. As for her healing him, by taking care of his wounds early, he wouldn't have to endure the pain which would stay until the wounds closed. Not only did her healing help ease his pain, but it also did prevent scars from appearing.
Why would she do all of these for him? It's simple—she loved him.
However, while her love for him alone was enough to justify her actions, there was also another reason, one which brightened and saddened her at the same time.
She wanted to take care of him before she could not.
While she was able to pass her power onto him in death, she wished she could physically be there to heal and protect him again. She knew it was not possible—to be revived after having stayed as a spirit for one hundred years—but she was certain for one thing:
Her trident which she had been taking care of was still as polished and shining as ever.
For he was her trident all along.