She may have chosen very striker-like powers -- I'd have to see the powers to be sure. However, the psion's a different flavor of controller than the wizard in any case. The wizard tends to have a lot of area damage and terrain-style control: zones of fiery doom, walls, and so on. The psion, particularly the telepathic psion, has more single target control. The at-wills are great for making it hard for a monster to do anything. Dishearten can render monsters unable to hit, and Mind Thrust sets the monster up to take a lot of damage pretty quickly.
I think it's slightly harder to control with a lower level psion because you haven't built up a lot of power points to augment the powers yet, and so much of a psion's control lies in the augmented at-wills. But the feel is always going to be different.
Something else to watch out for: psion can, for some people, get pretty dull because of the at-will structure of the class. When a wizard or a druid or an invoker gets to the point where she's choosing from four encounter powers, rather than mostly relying on at-wills... the psion will still be relying on at-wills.