I'm guessing the old kingdom/church/both sealed her in a dungeon where she could not escape or suicide, so her skill to restart was made useless, possibly the reset skill have a auto-save feature and after a while she was condemned to the dungeon, therefore who put her there had succesfully take care of her.
Maybe she was drugged or put to sleep with magic for enough time for the autosave to kick in, when she noticed it was too late, she could still astral project and donate skills, but that doesn't mean she could give it to who she wanted.
The reason for the seal is probably the usual, the people that summoned her feared her strenght after she saved them from whatever crisis they were facing, they couldn't send her back or kill her, so a seal was the only way.
Many times heroes get betrayed because the traitors are sure they will be corrupted from powers or start to clean human criminals.