I was breeding for a Shiny Charmander with a Blaze Charizard and a Limber Ditto... I got a couple Solar Power Charmanders, though very few (point being I bred a hidden ability onto a Pokemon where the mother did not have it). I also thought that DexNav encounters were the only way to find hidden ability Pokemon, and Y does not have DexNav. If the answer to my original question is yes, what is the chance?
Depends on the method. If you just use the Friend Safari, you might find it. If you find it in the wild, never.