I had a similar situation with where we used to live! We had an acre of fenced backyard that I let the chickens free range, and we lived in a subdivision with lots of close neighbors so there wasn't a lot of wildlife. I think it just depends on what you're comfortable with. There's lots of people who allow their chickens to free range all the time with no issue and others who keep them confined to a run all the time. I've done both.
At my old house, I didn't let my hens out until they were pretty good size. Probably wishful thinking but I thought with them being bigger it might deter some of the juvenile hawks. We had a few hawks that I spotted while I was outside with them and they never bothered us while I was out, they flew on by. I will say we had a lot of small birds in our neighborhood so they may have just preferred to go after the smaller birds instead of wrestling with my 5-10lb girls lol. The boldness of the hawk probably depends on how hungry they are, but we've never had one swoop in on our girls.
At our new place we have 10 acres in the woods, lots of predators of all kinds so they are no longer able to free range freely, but we have a very large run for them.
That was a long post to just say use your discretion and see what works for you! If you notice hawks hanging around, I'd say put them up until they are older and try again when they are bigger.