I've watched most of mine spawn. Depends on the pair, whether they'll let you watch or not. I leave if the male gets upset about me being there (like when he's flaring at ME!), but, usually, the boys couldn't care much less that I was there watching.
The nest needs to be big enough for the female to accept it and the male to feel he's done working on it (because they'll chase off an interested female if they don't feel they're doing working on their nest). Some pairs will spawn with little to no nest...some seem to require huge architectural masterpieces.
Sometimes they'll start spawning immediately, and sometimes it takes a few days. The only way to know which they're inclined to do is give them the time to settle it all for themselves.
You can release her for a while, and see how they react to each other. And then, if you have to leave for a long period of time and don't feel comfortable leaving them together, then you can jar her back up in the tank.