What kind of Glofish? There are different kinds of fish that now contain the glofish gene. Additionally, a lovely message on the official Glofish site reminds keepers that it is illegal to breed the fish. http://www.glofish.com/our-company/license-notice/
Doesn't matter if they do or not. Nobody will tell you how to successfully breed them without automatically admitting to breaching a NDA, or admitting to have in fact bred them illegally.
Don't expect an answer on a private forum such as this one.
Whether you actively tried to make them spawn or not, they still spawned and because they are actually a trademarked product you aren't legally supposed to raise the fry. . .
However, the ones you have are likely Danio rerio. You can look up how to breed those fish easily enough
But I wouldn't really bother with it. Just let nature do its thing and see what happens.