I did the exact thing for my wife. Went from the Phazer to the Nytro MTX. She likes the power but it is a bit of a handfull for her to throw around. She has tipped it over a few times just because she doesn't have the weight to counter the lean angle at times. Getting it stuck, for get it, also rolling it back over from its side she needs assistance.
I just ordered WCS front end kits and timbersled skids, hopefully this will help some. I put GYTR clicker shocks on hers from the FX 121 and now she likes the front handling much better. Im going to leave hers at 153 and Im taking mine to the 162. Im going to flip her track and I may put the 2010 rails on if need be.
She is 5'6 125