I've gone through A Mighty Girl and other booklists, and we have some books for DS. But what I'm finding frustrating is finding books that don't treat femaleness as a problem. Later on reading about the struggles of women for equality will be a good thing to give him some understanding, but right now I just want to show him worlds where girls are just people, not special marked Others. I don't want him to feel sorry for girls.
E.g. Rosie Revere, Engineer: great. Girl character, has confidence problem, gets over it and invents lots of stuff once auntie explains that failing is good. Not to do with being A Girl.
Zog The Dragon. Okay. Good in that you have both female and male characters working together.
The Pirates Next Door: Also good. Shows boy and girl making friends, plus PIRATES which DS is obsessed by. Relatively equal in sex ratio of main chars.
What else is there?