How old was your puppy when they could tell you they needed to ‘go’?

I have a 6 month old border collie, when I ask her if she needs to go toilet, she perks up and holds eye contact. I then let her outside. If she happens to need to go and I haven’t asked, there is no attempt to let me know in any way. She doesn’t always circle/sniff, sometimes she will be lying half asleep on the foot of my bed, and simply sit up and start peeing.

How old are puppies when they “tell you”? I ask her every hour/two hours, much more frequently than the length of time she can hold her bladder, so it isn’t as if she must be busting.

I praise and treat her heavily when she goes outside, and either redirect or ignore when she goes inside.