I think there should be a rare Magical Pie (Like the Philters) that ages a sylesti even more. It would of course be more expensive, maybe only purchased in the diamond shop?

Support for 1000 diamonds. \o/

For those who really can't wait. :P

edit: I was thinking that this would instantly make a pet an adult, so it'd probably be worth the price to some people.

I don't really endorse things that are too gamebreaking...but again, weigh your desire of want versus what you'd pay for it aha.