Differnet esp routine, i think..
Tell her to think af a simple figure like a square or something...and say dont think square because i already said it.. think of f you own!
OK, then inside or aoutside that figure think of another simple figure...
triangle and circle (those are the only ones most of the time) if she takes to much time you can neg her for being... stupid

If you want to take a step further before reveling the 2 sahpes tell her to put 2 different colrs in each shape quickly! (just like the 1- 10 routine) and the colors are red and green.
Good luck!

another one is: a number between 1 and 50, two digit number, both odds and both different, ok you got it?mmm 37! or 35