My teacher uses the Dohnanyi Finger Exercises Nos. 2,3,4,5,6, and 8 to teach correct finger positioning, avoid collapsing knuckles, and having the playing power come from the joint at the hand. They're not too bad, and if you take them slow (eighth note = 60) then she'll have plenty of time to concentrate on perfect hand position without worrying about dynamics and all of that.