When is it okay to leave my puppy out of their crate but alone in the house?

We have had our 6-month old puppy (not sure her breed yet, waiting on Embark results but seems to be lab/golden retriever type) for about one month. We have been crate training her and so far it’s going pretty good. She does whine but settles herself after about 5-10 minutes and is good for about 3-1/2 hours by herself. Have not left her alone longer than 3-1/2 hours. How did you get the puppy used to free range in the home? We will puppy proof when the time comes. Is it too early? Does she need to stay in the crate for a longer period before we think about free range? TIA. 🐕