Well... prior to Dawntrail we only ever met male Mamool Ja of any kind, so maybe we'll meet one of them, or at least hear about it at some point. If for example there was one more blessed sibling, who just wasn't old enough to compete yet, it would make plenty of sense for the Mamool Ja to hide them away from any prying eyes and raise them in some secret enclave, so their perceived enemies couldn't do the same, as the Mamool Ja did with Wuk Lamat.

But if a female blessed sibling existed, it would beg the question if a male and female pair of them would be able to conceive children togther. We know that two-heads are exceptionally unlikely to have children, but as far as we know that was from a two-head with a one-head, not two two-heads together.
Speaking of children (or rather the single child) of two-heads... I hope we'll also meet, or at least hear about both Zarool Ja's mother and partner. Considering how Wuk Lamat had this Hyur mother figure, I would imagine that Zarool's mother either died before the kitty was adopted into the family, or shortly after, or that Zarool came from a fling, rather than a marriage, with the mother leaving the baby behind and hightailing it, neither of which would exactly have added to Zarool's already strained mental state.