3 month old puppy won’t go toilet outside.

I’ve only had her for 6 days so I’m completely understanding that she won’t get it within a week, however, once a month we visit family and stay for the weekend due to being 2 hours away.

We can’t stay there unless my puppy is toilet trained to go outside, and obviously we’d prefer her to go outside as well.

Currently she’s using puppy pads and we’ve gradually moved location of them. She’s now urinating right next to the back door which I think is a massive positive step, but she’s still pooping somewhere else away from the back door.

I take her outside after naps and playtime, as well as when I see her needing the toilet, but this girl just refuses to go.

Last time I took her out we were outside for 15 minutes. As soon as I got her back inside she went for a poop in the living room on her puppy pad.

I have 3 weeks before we’re going to stay at family’s so ideally she’s toilet trained within 3 weeks. Any suggestions would be great as I’m a first time dog owner!