Congrats on your beautiful little BOY!!!
None of my lovies have been DNA'ed (or laid eggs, for that matter), but I'm 99% sure Nin is a male and Leyla is a female, just because of their personalities, stance, head shape, etc. Nin's beak does have a pointy ridge and Leyla's is definitely rounder.
I've been calling Kermit a boy, but there are days I wonder if "he" really is a "she". I eventually want to get him DNA'ed. He regurgitates and flirts with toys/perches, but he also makes female flirty noises and is female-y territorial occasionally. I know lovies can exhibit behaviours of both sexes sometimes, so his actions probably don't accurately indicate his gender! His beak is a bit rounder like Leyla's, too, though, now that you mention it! Now I'm really interested to find out if "he" is male or female.