Got through it, killed the hag, etc etc... what is bothering me the most right now is if you have Speak with Dead you can't use it on you-know-who's dead you-know-what. Seems like a missed opportunity to tell this person to get the fuck on with their life. I have save scummed and exhausted that conversation and every path it can take and it still.. honestly, it sucks. Straight up just 100% sucks that there isn't even a skill check to try and make them see a lick of sense.
There are a lot of these quests that seemingly will continue when you reach Balur's Gate, so not all hope is lost.
If you let her keep him she says she'll go to BG to see if someone there can help