clown fish laying eggs

[Alberta-newb]

Congratulations! I hope you don't mind I hijack this thread a little and ask a few questions.

At what size do ocellaris clowns reach sexual maturity (ie. start spawning)?
Do they require an anenome to spawn or are they comfortable with surrogate hosts?

My pair are currently only about 1.5" long and were sold as a true pair which I believe is true. One is slightly larger and is the boss (female?) but they are not aggresive to each other (she does on some evenings push him out of their host). They have ignored my torches and frogspawns and decided to host in my giant featherdusters instead.

Thanks for letting me bud in