WARNING LONG SEMI-RANTISH :)
Disclaimer: Please note that I am not a qualified person, although I do play one at work.
The first nine pages do fairly well keeping the setting very gender neutral. We do see good Queen Leanan and evil King Slaugh and all the art shows somewhat gender ambiguous male and female faeries. The pixie description even does well right up to where "Late each night, a pixie curls up inside a friendly flower to sleep. The petals close around the pixie, protecting her while she dreams, and open to greet the sun at dawn." I definitely can't read that as is to my boys and have any hope of them playing pixies. "Late each night, pixies curl up inside friendly flowers to sleep. Across Brightwood, petals close around the sleeping pixies, protecting them while they dream, and open to greet the sun at dawn." None of the flavor is lost and yet I now have a chance to get my boys to be pixies without having to reword what is written. Also, the only art for a pixie is a classic "Tinker Bell" style pixie.
Page 11 "Faery Lore: Pixie Led" has the pixies misleading a female traveler. Also, the description on Brownies suffers the same issue as pixies: "Brownies are sensitive folk, and a brownie who feels put upon by her adopted family usually turns to pranks to even the score; stacks of dirty pots mysteriously fall over, clean clothes are found spattered with mud, bowls of porridge are upset, and so forth until the brownie feels satisfied." It's easy enough to just write "and brownies who feel put upon by their adopted family usually turn to pranks . . . and so forth until they feel satisfied." Again, the only brownie art is a pointy eared little woman.
On page 12, we again have a Faery Lore box, this time Cold Iron "instantly drains a faery’s magical life force, causing her to fall into a deep healing sleep" instead of "instantly drains the magical life force from faeries, causing them to fall into a deep healing sleep." Another female human falls victim to faery magic via Faery Rings.
The sprite description has "Dancing gracefully through combat, a sprite parries and strikes in perfect time to a joyful song of battle only she can hear . . . ." It could just as easily been "Dancing gracefully through combat, sprites parry and strike in perfect time to a joyful song of battle only they can hear . . . ." Despite this, we do get the idea that sprites can be male from the art on page 13.
The pooka description on 13 states, "She gains the abilities of the chosen animal . . . ." Again, why not use "They gain" to keep thing gender neutral? The pooka is also described as giving human travelers wild rides before "dumping her [the hapless human] into a distant pond or lake." As with the art for the pooka is likely male,it is somewhat ambiguous but if that's a womans face...eww! :)
I could go one with each page but will, instead, summarize: Not once, excepting in the story and narrations, is a feary described as male and yet throughout we have descriptions of female faeries. Other than the two male faeries in the narration, we have the Goblin King and the visible villains of the narration, the troll and goblins. The art is better at portraying male faeries but by the time we see those images, faeries being female is already fairly well entrenched but even the art is slanted. There are 18 pieces of art (two are repeated). Three (one repeated) show a male faery only (assuming the pooka is male). Four more show definitely male and female faeries with one male goblin thrown into the mix. One is ambiguous enough to pass either way but leans more toward the feminine side. The other nine show only female fey with one hag thrown into the mix. The art falls, roughly, with seven for the males (with one evil goblin in there) and thirteen for the females (with one evil hag in there), better but still nearly two to one.
The good vs evil, female vs male issue is not nearly as stark but with the above slant in place, it seems more evident. King Slaugh is evil, the evil troll and goblins in the story are all male. True, page 14 says of faeries who become goblins, "She loses her former form and gifts, taking on the hideous shape and awful powers of a goblin." Again, though, this only increases the faeries are girls feel from above. Hags are also inherently female so that does help balance this some but the ultimate incarnation of evil is the Goblin King and the ultimate incarnation of good is the Faery Queenx2, Leanan and Selene.
Why do I feel that any perceived gender bias is a big issue in this? Because, as Don noted, faeries are most often seen as being either female or feminine. Tinker Bell, Winx Club, fairy godmothers, fairy princess and the list continues. Do an image search on fairy or faery, how far do you have to dig to find a masculine fairy? OK, how much further do you have to look to find a masculine fairy that isn't simply a girl fairy without the curvy bits?
Intentionally, maybe, or unintentionally, more likely, the manual follows the feminine fairy motif and adds a very mild dose of women-good man-evil into the mix. Balance out the feminine fairy motif and the good/evil dichotomy will disappear completely into the background. Keep the genders neutral and you'll have masculine pixies and feminine pookas and everything in between.
Having written all that, I do love the setting and the rules. I could go on at length about that as well but I figure that you've heard enough from me today!