There isn't much difference against her at level 30 and 40...but some important things:
In lv 30:
a)You will not need Riryoku Field...
b)Always set at least one dimension gate on your field (don't worry about Swift Birdman Joe) because she will always summon it before Garuda, so just right after she actvates the effect of Garuda, you activate your dimension gate.
c)Farm Successful