I just bought my first bow. A browning micro Adren hx. Mine is a 40-50. I've not been shooting long and started shooting at 40 and am working my way up. The most important thing is to be comfortable for awhile with the bow, just to get the feel of it. You use muscles that you never even knew you had! or at least I am!!!! If she can pull back 40 and seem comfortable with it, I'd definately go with 40-50 # bow. It would suck to go with a 30-40 # one, and then her not being able to pull back as much weight as she desires. But, that being said, for some women pulling 40 # is alot and she definatetly doesn't want to be pulling back more than she can handle! Good luck!!! =D