She is adorable! How fun to have a play date with another YT'er.
When Max was a puppy, he didn't want to wear a harness. He forgot about it the instant I took him outside. Same with the leash. At that time, we had a mesh vest harness that he had to put his head through.
When we switched to the BB, it was so different and comfortable that I think he was fearful that he wasn't 'hooked' up to me.
Once again, the instant we were outside, he forgot about it.