I had a couple of pairs of these back when I ran my breeding fish room, the males are usually ever so slightly humpy, even at that size, and they tend to have flicked fins. Also- often, but not always, the male won't have the black line going down from the eye. Not a dead cert as some do, but nearly all females have it so it helps to sex youngsters. I would definitely say this was a female.
As everyone says, the only way to be certain at this size is to wait to sex the tubes, that should be pretty obvious once they are out.
Just my two cents - watch her for Hex, I've lost a couple of them to that, they are a little prone to it. Just watch her for stringy white poop. It's a sad way to lose a fish!