Hikemore basically summed up what I think about this scenario and I agree that meeting a group of people of mixed sex is generally safer. Also as Bacpac stated, a single person (female or male) is more vulnerable and to take that one step further, this applies to almost any survival situation

That said, in my area and my experience, there are a lot of single female hikers and campers who are by nature, are wary of any other people. However once they size you up and decide on how safe they feel, most women are receptive to talking and sharing notes about their hiking, camping etc. (Met an ex G/F this way and she nor I, worried about who was carrying a hidden hatchet...)

Would this be different in a disaster type situation where the woman may not of had much prior solo outdoors experience? It probably would and I would think that a woman would avoid any one single point of contact and probably seek out people in a group as their first choice.