[@Sola] Of course. So how I see it is that the Fae go through Rebirths at the end of their current life, or whenever they really feel like it. Rebirth's only act as a renewal of their life force, giving them magic back. Age would just work in how many years they have lived for, they retain everything from rebirth to rebirth. I suppose if a Fae didn't want to retain their memories, they could start over but it would be a rare occurrence. 

As they grow older and their magical abilities blossom, they are able to undergo changes to their physical appearance. Say as a mark of age and power. Truly old Fae could choose to look like anything they wanted, even young, but as a cultural norm they choose to look older in appearance. They can be very vain, and looks determine place in their society. Young Fae are at the bottom because they don't hold mastery over their powers yet. 

Does that help?