a more accurate statement would be "there's just not many freakettes on SF", and most of us guys dont know the womens range as well as we know the mens range
when you say trek, what do you mean? lots and lots of walking? or off road? or?
lots of the nike6.0 stuff is made to be a bit tougher and a bit cheaper than most nike products. they wont have the cushioning nor tech of the latest stuff though.
i have friends who on their treks either wear "keen" or "northface". they trek through the bush/country, climbing over rocks/mud/trees/etc and carrying their stuff on their backs.
i have other friends who describe walking all day round the city trekking to the various stores. they mostly wear whatever they like. anything with lunar in the sole should be comfy. perhaps the lunar eclipse or something suitable for her foot type. the shield pack stuff from nike is all treated to resist water. useually a bit tougher than the same shoe not shielded.
please note i've randomly ganked pictures off the net. i suspect there may be fake colourways
some other randomish shoes
Nike Zoom Meriwether "Deep Burgundy"
Nike Woodside Chukka II Women's Boots