My wife and I are dog sitting for some friends while they go to the beach on vacation. She is only 14 or 15 weeks old. They got her from someone who got her from the breeder. (Probably a backyard breeder) the original owner said that his other dog, I think it was a small breed dog, didn't get along with the puppy and needed a new home. The puppy is mostly normal other than a reserve towards men.

Our friends know that we are great with our dogs and want me to work with the puppy. I know that a dog is a dog when training, but I am wondering if anyone has any experience with Great Danes. She seems to have very little drive for toys or treats. I only want to work with engagement right now and basic house manners because I know she's still growing and developing very fast and don't want to hurt her in any way.
I guess I don't really have a specific question, just if there are any tips for building drive and motivation in a puppy that has very little? And if there are any words of wisdom for a first time Dane owner?

I had a Dane x GSD when my daughters were growing up.

Danes and all large breeds can mature VERY slowly.

Are you marker training?

Have you tried food reward?

Does the pup chase a ball?

Another thing is if the pup isn't used to you it could take a few days to a few weeks for the pup to be comfortable you.

That can vary considerably from dog to dog regardless of breed.

I have a similar problem. None of my 4 dogs tugs properly. So I thought it must be my error somehow and still think this. So I purchased Mark Keatings courses "Rules of play" and "Relationship Games". Wonderful courses by the way, but my dogs simply don't tug properly.

One of the Pits and my Lab Mix do it sometimes, when they are in the mood, normally late in the evening. But this happens seldom. They have no problems with games like Hide and Seek, they also chase a ball or other toys.

My second Pit and my adopted Stray don't tug at all. Slippie, the Pit, doesn't even pick up or grab a toy. She is not interested in such games at all. Except, when she can steel something from one of the other dogs. But I do not play with them together any more with toys, because Slippie can get veryaggressive when an other dog has something.

I do marker training. Mark Keating said I should not give food rewards when tugging. I should let them win, then give my release marker, step backwards and the reward would be, that the game continues, when they bring the tug to me.

Perhaps I should add that I didn´t play tug with the Pits, when they were Puppies. I was totally inexperienced and played only things I had seen from other people, throwing a stick, a coconut, a ball. Only when I took Marks courses about two years later I learned or should have learned how to play.

But somehow it doesn't work properly, although I move the toy like a bait which flees in the last moment before getting caught.

The stray and the Lab~Mix lived on the street the first 1 1/2 years of their life, which means no one played with them at all.

Can this delay be one of the reasons? Or what the hell am I doing wrong?

Danes that I have known were easy going, gentle and very mild, without much drive.

They seemed like super nice dogs.