I think she'd be better off getting Class Training to get her unarmed damage up first (and Improved Natural Attack since I don't think she has that already; it's roughly equivalent to two class trainings).  Hard to argue with dealing damage like a level 20 large Monk (4d8) before Mighty Wallop or Expansion.  (Then, add in Mighty Wallop, advance manifester level until you can use Expansion to go up two sizes, and deal damage as a level 20 colossal Monk [12d8].)