I believe what's going to happen now is there going to start working their way down the tree, and then back up before they're ready to venture off on their own for good.
The parents are going to still watch over them through that, and possibly through the first winter, and then they will be out finding their own territory, to raise the next generation of owlets!
I've had a few small birds nest under my porch roof and right on my neighbor's door wreath is also a very popular spot, so I've gotten to watch a bunch leave the nest and I always wonder how they know they're ready.