Welcome to BYC! Your girls are lovely.
I'm no expert, but my birds do free range during the day when I am home. Otherwise, they are securely closed in the most predator-proof coops I can provide. My approach to easing them into free ranging is to make sure they are accustomed to their coop and view it as home, sweet home.
They then get to move to an attached run and slowly are first allowed closely supervised freedom -- in other words, me staying outdoors with them the whole time. Once they seem comfortable and I have stopped being a worrisome, overprotective mom, I leave them alone for short periods of time -- while frequently checking out the window.
Even then, there is a short fence that wouldn't prevent the better fliers from going over but seems to make them believe they have to stay to the south of the house where I can see them. Most of my girls are larger and only take to flight when they absolutely have to.
All in all, it's a bit like training small children -- except the chickens are much faster and can fly off a bit! Long before they get any freedom, they get used to hearing me yell, "Chick, chick," which either means a meal or chilled grape treats are about to be served. Food is the best motivator!
Good luck with your new flock, and yes, it's easy to fall in love with them right away.