Like Lux said the only 2 times she was damaged was because of the heroes and hostage safety. She really should have went alone and kill Orochi right away.
Something that's bothering me about the art is that there seems to be a lot of inconsistency in when Psykos body is split in half and when it's together.
Like in all the action shots it's split but interleaved with those are reaction shots where they show her face not split.
I'm trying to understand if there is a secondary body that never split but it doesn't really seem like it.
It seems like a continuity error.
EDIT: Ehh I think I get it. The big version of her that splits is a kind of gooey projection. Her real body is inside the pine cone on the monster's forehead between the projection's legs. It's kinda confusing which is which though and it's not clear where the pine cone goes during some of the scenes.