when she uses her ability to add a foundation as an attack into the card pool, do you have to make a control check to PLAY the attack... or is it just added?

She makes a check against the 3-difficulty (+progressive). Essentially her ability is "Play one foundation from your staging area face down into your card pool as though it were a 3-difficulty, 3-speed, 3-damage mid attack with Chaos/Death/Void".