A sequel series to Avatar - The Last Airbender? I am so there! The original had some solid female characters, too, as you mention.

I've never noticed a 'helpless female' schtick in the DC animated stuff. And I really loved that they played on that with the almost relationship between Batman and Wonder Woman. At one point they're on a rooftop, and she's basically saying they should go out. Batman says he doesn't date because his enemies would try to get to him by hurting those close to him. Wonder Woman crushes a lump of stone with her bare hand, and asks for his next reason :)

I love Lilo and Stitch