I DID THE EXACT SAME THING!!.....i really regret cutting it all off....it used to be down my back and now my hair is barely past my shoulders....oh well...=/
In the pic she really doesn't have "big hair" she actually has a small face. It looks like she just has good volume.
^^I'd say this is the way to go! Blow drying upside down is really optional but the reason it's is suggested most times is that when your hair cools from the heat of the dryer it cools away from your scalp keeping the volume.
Probably straightened it with a blowdryer possibly to keep some volume instead of using a flat iron and then used a round brush and curled underneath or used some big rollers and set her hair that way.