The body Lilith received from Jedah was the image of what Lilith wanted to be - an imitation of Morrigan, but she couldn’t become Morrigan completely. Fans speculated that her childish look possibly comes from her own feelings of not being a perfect existence, like a girl who has yet to become a woman. However, it is said what with the right amount of power and belief, Lilith could even become a man if she wished to become one with Morrigan.
Well there’s an idea… Lilith as a man might be a great start for a new fan fiction. Although if that were to really happen in the game, fans might either be disappointed or very supportive. Thanks to Janice for sending this in!