Gith have pretty deep knowledge. Maybe they are mammalian in how they give birth, but their females do not have time for gestation. So, the zygote is removed from the female soon after conception and is placed in an egg shaped fertilization chamber (with an environment made to replicate a gith womb).
Perhaps the process also gives them some sense of familiarity with their dragons because they are eventually “hatched” in a fashion similar to their mounts.
Whaddya think? Better than imagining Lazeal with a cloaca or a hyper flexible pelvis, at any rate ! Lol