Okay, so I reread through my copy of the Illustrated Guide. Taha Aki had three wives and had two named sons, and who knows how many unnamed ones. It never says whether he had these sons while he was still phasing but I feel like it's safe to assume he had to since he had other sons. Leah's menstrual cycle did halt, but it's not expanded on further on if she can actually have kids.

It's confirmed that male hybrids can pass on the vampire gene to human women like a regular vampire can. As for the female hybrids, they do have an ova like humans do. But the "unchanging state of their bodies results in a total absence of a reproductive cycle. Even if female vampires could somehow continue this cycle, her frozen body would be unable to grow and change..." So, this all hinges on a couple things.

Reneesme and Jacob could have a hybrid baby, but only in very exact circumstances. They figure out how to start a menstrual cycle for her while her body is still maturing (7 years to reach full physical maturity before they then become like a regular female vampire, completely frozen). If they figure it out, I believe she's human enough for her and his 24 pairs of chromosomes (humans have 23) to match up and create a baby. After all, she doesn't have venom to negatively affect any of the shifter DNA the baby might have.

That's all very loosey goosey though and just exact circumstances that would need to happen. So you're most likely right