what difference is there between male and female Nomai?

i don't mean to be offensive or sound homophobic at all. i'm just curious. Harthians aren't gendered, but Nomai are. they're referred to as "he" and "she", but what difference is there between them? and there's Daz and Cassava, who are both male, and are married. how do they, and can they, procreate? or is it like human same gender couples where they'd have to adopt?