Thank you for your email. My advice would be to continue flying your Barn Owl on the creance daily and to continue to free loft her in the weathering, provided it is large enough.
The smallest size weathering I would recommend would be a minimum of 6ft X 6ft, though the larger the better. The weathering should have two perches as far from one another as possible, so that the owl can fly from perch to perch.
Here at S.O.S. we free loft some of our Owls from their aviaries which are 8ft X 12ft, each with 3 perches.
Suffolk Owl Sanctuary