My female students see no real differences. What they do say is that SOME of the female specific BC's are bulky and use too much material. A number of female divers on this board like backplate and wing combo's because of the huge range of adjustment and once it is adjusted it stays there. I have also found real success with the Zeagle Express Tech as it is so similar to a BPW but with a plastic pack. I am 5'7" and weigh 165 or so. I took mine and have had it on a kid who was barely 5 ft and 100 lbs and on a female 5'9" heavier than me with a how shall I say "generous" chest and fitting it to either of them took about 5 minutes tops and both liked how comfortable it was. Many recreational bc's in general are uncomfortable, have poorly designed pockets, not enough d rings, too many drings, or not in the right place d rings. I recommend taking a serious look at your self and the diving you think you will do in the future. Look at your budget. More money does not equal a good product if it does not fit you or do what you want it to. If it has pockets, clips, rings etc are they where you need them and can access them easily? A $600 ScubaPro jacket bc to me is worthless. My $250 Zeagle is worth ten times that in it's convenience, fit, utility, and ease of adjustment.
Although I totally agree that the exp tech is worth considering, not everyone prefers back inflate bcds.
There are lots of good women's bcds out there n she should really try one on for size.
However, if back inflate is your thing I really like the express tech n this package from scubatoys:
BackPlate and Wing Package reviews and discounts, Dive Rite
Get the deluxe harness n you've got a durable setup even you can use : )
SangP