1. Answer: It depends on everyone's taste and these rankings change all the time. According to RankMyPorn, at the moment, the top ranked 18+ Teen Female Pornstars in the world are: Veronica Leal, Nia Nacci, Alina Lopez, Kenzie Reeves, Veronica Rodriguez, Elsa Jean, Melissa Moore, Jewelz Blu, Eva Lovia, Jessa Rhodes, but these will change based on what people vote.
2. Answer: It changes. You can see the latest rankings on RankMyPorn.com and also vote on it for free.