Now I understand what happened in that scene from reading your post. I think if she didn't leave her meditation, Thossapol would've been killed by those evil gang though. So then she wouldn't be able to save him in time. When she becomes human then she wouldn't have anyone left as well.Spoiler below read at your own risk if you haven't watched.
Because she was supposed to wait til the eclipse pass and let sins and life happen as they should and by going down there she entangled herself in the sins of the people below (what her grandpa said while she was meditating and before her mom killed herself). She left before the eclipse completely passed so it ended everything she worked hard for, for 1000 years.