What are you talking about, that wasn't shown in the flashback at all.
The Empire invaded, they got slaughtered and taken hostage.
Stop making things up, thanks. It wasn't even hinted that she did it on purpose why would she even do that? It doesn't make sense, she is a chief already, why would she sacrifice all her subordinates for a "scheme" like that.
She is seeking revenge, and it can't be made any clearer than that. If you really believe she did it to rise in rank or some shit like that, I don't know what to say.