They did have concept art of female moles that would be randomly running around in the Dragon City, but they were cut... But yeah, Cynder and Nina are the only female characters in the whole series. But the original Spyro wasn't much better, there were only 4 female characters that often appeared in any of the three original games...
But it still had heaps of females, and there are only that amount of main male characters too, you know, maybe a little more.
Zoe
Bianca
Elora
Sheila
The Sorceress
All the female characters you have to help out. Such as that ice skating bear in Icy Peak and that girl in Desert Ruins.
And the female baby dragons in YOTD. I'm sure there was heaps of them. I mean, you don't see a male dragon called Ruby or Kiki.
And there was Ember, Nanny and Ineptune (spelling?) in AHT, and I think one of the dragons in SL was a female too.