Am I the only one who personally thinks that her magic isn't actually healing and precognition but rather "time"?
i.e. she doesn't heal her wounds but rather turns time back before they happened.
Also, if that's the case I'm wondering if she, in order to disappear, could use her reversal powers and "kill" herself, get her body transported away and then "resuscitate"? Though to use the magic in such an extreme manner she may need to strike a deal with god and give up sth. in return like e.g. her eyesight which she gladly accepts, additionally as punishment for leaving/traumatizing her family and friends.
Anyway, I don't think the king is aware of (the full extent of) her powers. Rather her vanishing for good has something to do with his son's fate of being born with "a phase of losing something". But this chapter furthermore revealed that Rasmere seems to have the power to break through his fate. (Still want her to disappear for a few years though and not let it end with a pathetic, half-hearted attempt because of the prince. Let them suffer for a bit hehehehe~)
Btw most babies are born with blue eyes and blond/light hair (in Western/non-Asian or African countries). The color of both starts settling after approx. 6 - 12 months after birth, so the fact that little Glen already has green eyes is a bit off-putting.