As you know, having played the game for years, all pet talents are given randomly. There is never a guarantee any pet will get Spritely (or any other talent). Example is the tons of Starfish I have... one of whom has learned spritely. The other 6 or more, nothing.
It could depend on what pet you hatch with. If you didn't have any pet during the hatching process with spritely, you probably wont get one with it. Hatch with someone that has that talent. I have a few pets with spritely if you want to try and hatch with me.
@Miranda: Why else would she trying to train her pet for the sake of getting Spritely?
@Angela: Here's a tip. If you have 38 Mega Snacks, you can get any pet to Epic. I calculated. 3 from Baby to Teen. 5 from Teen to Adult. 10 from Adult to Ancient 20 from Ancient to Epic. Anyways, it would take 40 more Mega Snacks to get to Mega, So really 68 Mega Snacks. Another problem is you are only training it to adult. (Try to train it higher)