She is 12 weeks old on Friday (so she's getting her injections on Friday

).
She is kept in a cordened off area in our kitchen (about 7ftx5ft) between 9am and 3pm, while we are both at work. The last two nights she has not even wet her pee pad! I get up a 7am and bring her for a walk and then again at 8am. Yesterday morning, she went out and had a pee and poop. This morning, just a pee (she was about to poo but I had to bring her inside as my wife got locked into the shower!!!! and of course the inevitable happened and she pooped inside). She already seems to have copped that outside is where to go toilet, but how do I get her to tell me "Hey, I need to go out" because at the moment I'm watching her like a halk for the signals!!! I bring her out every hour.
The growl she does isn't a playful growl (she does the wee playful growl too, that, I don't mind). She's maybe done it three times since we got her (3 weeks ago). In each case it is where we'd go to pick her up, but you'd be afraid to pick her up. At the same time, I'm afraid not to pick her up because I don't want her thinking growling at me or my partner is in any way acceptable.