This is Jade's awkward phase. It takes her a while to grow out of it. She becomes a gangly teenager and her horns start to grow disproportionately large, whereas her tail and wings stay small. Her voice barely changes until she is in her late teens.
Teenage Jade is self-conscious about her appearance and high-pitched voice. She has the same troubles and conundrums every teenager deals with, but is luckily not dealing with much peer pressure. Her established personality stays mostly intact. She slowly matures as she gets older. The only big change in her personality is that she becomes a lot more patient.