#1) Depending on the age of the plant(s) that went into 12/12, you could see pistils within a week or two, if not sooner - I'd be checking daily.
#2) That's plenty of light for clones and a smaller vegging state, just make sure the other requirements are met.
Hmmmmm, just re-read your post and with the age of those plants, the should show pretty quickly, especially the four month old ones.
Good luck.