As Lab Rab had commented there,
since the owner of the home traditionally makes Hamotzi (as recorded in the Talmud (Brachot 46a), בעל הבית בוצע ואורח מברך), when a woman is hosting she should make Hamotzi.I find myself agreeing with him. The only exception to this of which I can think might be when the person who brought the חלה (hallah) is given it to make "haMozi" rather than the host/hostess, as they brought the bread, themselves.
So I asked one of my fellow diners, Margueya Novick (you made it onto my blog (and I spelled your name correctly, too)!) as to why the young ladies at this meal, perhaps in general, even, were taking no interest in making these blessings and giving them over to guys. She responded that at one time she actually used to be at all girl meals and she, or other girls, used to make blessings, but feel kind of on-the-spot. However, once she started attending meals with guys, it made it easier for her that guys would be taking care of that. (Margueya, I hope I got that right. :))
I'm not quite sure I understand that line of thinking, but I guess it is what it is and people do that. While I very much like the statement in the Talmud mentioned above (and for which I try to be מקפיד (careful)), I would suppose that in cases where the person doling out the bread at the meal is doing it as a שליח (proxy) of the host or hostess, they will hopefully give it out with good quantity to their fellow diners.
***As with all of my posts, this is not a פסק הלכה (judgement of Jewish law), as I am only in rabbinic school, and not yet an ordained rabbi.***