I really don't think Jeph is going to show Momo lusting after a human male in her current chassis, because she looks like a young teenager and that would be really creepy.
I do think the apparent age of her new chassis has something to do with it. Momo might be avoiding revealing those thoughts because of the squick factor. It is also possible that her long term plan is to gradually age as she jumps to new chassises, paralleling her growing experience as a person in the world.
Actually I think there's an interesting conversation we could have there, especially since
1. This is a world where digital sentients exist, and can/do interact with organic ones, and share a whole lotta characteristics with them.
2. This is also a world where a digital sentient can change its physical body drastically.... assuming it can afford to.
Is it okay to be squicked out by a relationship between an adult AI and an adult human? Or perhaps I should ask is it just to act on such a squick? These aren't humans, after all, not the AI, no matter how human-like their chassis is. They are our sibling-souls, but so's Chewbacca, and he's a wookie not a human.
And what about our spider-chassis friend? The toaster? If they're of an interest to have a romantic and/or sexual relationship with a human, should we really be off-put about that?
I feel like we're probably getting into 'Her' territory here, though, and I didn't watch that movie, so y'know.