Reggie mentioned these important demographics in an E3 analysts meeting.
Nintendo is looking to get a lot of future 3DS sales from kids, and also to get a lot of girls of all ages playing as well. This was the intention that NOA President Reggie Fils-Aime divulged to analysts at an E3 briefing.
Nintendo's intention to target younger demographics became clear with the release last year of the 2DS version of the hardware, a less expensive version that lacked the 3D effect and any associated health concerns for younger eyes.
It also isn't new for Nintendo to target female players. The company has several specific franchises, like the Style Savvy games ("Wagamama Fashion: Girls Mode" in Japan), or the Animal Crossing series, that have seen a lot of adoption outside the stereotyped idea of only the young and only the men being the only ones who enjoy videogames.
Nintendo's 3DS family of systems has already moved more than 43 million units worldwide, so it remains to be seen how the gaming company angles its upcoming lineup of software and promotions to achieve its stated objectives.