House training - when can a dog just roam?

Dogs are good with schedules and learning to anticipate you. If you make a schedule to take her out 4/3 times a day and in two of those times, make sure she actually goes, she will catch on to when she is supposed to go outside to potty. Does she have restricted areas in the house? When you first trained her did she have potty pads or was it straight to outdoor going? I might suggest you have a potty pad inside so she knows if she has to go there is one spot in the house. later on, she will get in the habit of going outside and you won't need the potty pad. It will just prevent messes in random places of your house.

Something you might try to teach her to signal when she needs to go out is using potty bells! They're bells you hang on the back door (or whatever door you regularly take her through to go potty). When I first taught my labradoodle to use them, I would ring them every time I took him out to go potty. I would give him a short period to go (30 seconds, 1 minute at most), and if he didn't I would put him in his kennel and then try again in a few minutes, ringing the bell once again when I took him out. This way they start to associate the bell sounds with going out to go potty only (not just going out to play). As he got older and started understanding the concept, I would have him be the one to ring the bell when I took him out. An easy way to do that is to hold the treat behind the bells and when he went to get the treat his nose would also hit and ring the bells. Same drill with putting him in his kennel if he didn't go. After a while, he started ringing the bell on his own when he needed to go out. The key is consistency!