When can I realease my betta female fish into the males tank?

Currently I have a small tank with the female fighting fish in it, inside a bigger tank that has the male fighting fish. This is only very recent – and it is so the male and female fish can get used to eachother before I let the female fish out, so that they can breed. I’ve heard I should keep them this way for two weeks, then let her out, but I’ve also heard I need to wait for the male to make a bubble nest and for the female to have eggs before I can let her out. So I am a little confused. Any help is greatly appreciated.

Why is it that so many people who know nothing about Betta breeding insist on trying to?
If you don’t know what you are doing, then don’t do it. If Bettas aren’t properly conditioned they will very likely try to kill each other.
If you did manage to get a successful spawning, what will you do with all the fry? Fish stores won’t take them, they have contracts with their own suppliers. All the males (possibly dozens) must be housed in separate tanks. Do you have the space and money for dozens of separate tanks? Then what? Do you want to spend the next 5 years or so taking care of all of them till they die of old age?
Just enjoy your fish, and leave breeding to the professionals.

Female Crowntail Betta Fish