The card argument isn't valid : She was dropping Tataru, Lightning and Urianger at the end of 2.55 and now she drops Tataru, Lightning and Firion.
And none of the cards are exclusive to her.

About the hide, she could have ask Edmond for a little help (Edmond isn't poor as far as I know)

As far as I read things, she seems to hide something but it may not be about betraying us. It could be a new (or old) friend that rather stay in the dark for now. Wait and see ^^