I just got my lady a 2012 gnu b-nice in a 148 because it was a great deal. Now I am second guessing the purchase and think she needs a shorter board. Probly the 144 would have been better but it would have cost another $100.
She is an athletic chick and just started last year on a friends burton social. She is learning quickly and likes speed but is still a beginner. 5-3. 125 lbs. size 7 shoe.
She can ride the '48 for sure but my wife is practically the same size as your lady and she rips a '43 and a '44 anytime we're at the resorts. She will use a '48 off the sleds in the backcountry with super deep pow.
Remember it's only a good deal if it's the right product at the right price. I'm sure if it was a '53 you still wouldn't want it even if it was cheaper than you paid for the '48.
I'd say thats perfect for her, the weight range on that board is like 80-160, better to be in the middle then on the heavy side of the spec. She will feel more comfortable riding fast on that then the 144 type size.
im about 173 cm and ride a 156 lib skate, which gives a ratio of 1.1 (my height / board length). your girl has a ratio of 1.08, so her board is shorter for her height than my board is for my height. she should be good with it.
My GF rides a 149 and weighs 140 or so... Not very athletic. A 125 lb athletic person should be able to manhandle a 148 no problem methinks...
Besides, unless she's planning on doing a lot of spin tricks in the park, or is brand new to the sport, there's nothing wrong with going longer anyway. Longer = more stable in chop, better float in pow, etc.
My daughter is the same size she has a 144 for a jib, 148 stiffy cambered for a bomber and 155 for deep poo. She is athletic, loves speed and easily hits 45-50 mph on the 148....infact she thought its not big enough cause she maxes out. So in an effort to go faster shes switched to skiing fatty twins...last year on 169 k2 misdirected and this year on some surface skis that are 174cm and are 121mm underfoot and 154mm at the tips. Its not the board...its her determination and aggressiveness. The 148 b-nice should be just fine...especially if she likes to bomb.
bomb on skis