On the topic of that last post, I'd actually say keep both of those on hand! The girl on the right gives me a sort of burly tomboy impression, while the left one gives me a more standard girly one. Both look like the same character though, might be worth trying to slim the limbs down on the left one some to make it more distinct?
As for the walk cycles, the legs look fine but I'm noting that the hips aren't really moving along with them. It makes the legs look like they're only swiveling along one axis, when walking is really kind of a gyrational movement. Study yourself taking steps from various angles and in different strides, you'll sort of see what I mean.
As for differing the males from females, I'd say you're honestly doing fine there. I can tell between them at a glance, and that's without any more defining characteristics like different hairstyles or clothing choices to push that envelope further.
Try some different outfits on them to see if it still looks weird to you, as it is they're both in pretty androgynous outfits (red tee and bluejeans) which, to me, often tends to bias slightly male mentally speaking.
