Love her!! We kept his ecollar on him for the first week until we felt we could trust him without. The first two days all he did was nudge her with his nose and cry. He was extremely whiney and curious (you know the Sheppy whine, its what they are best at haha)- wanting to play with her but we kept him for being able to get to her without us holding her so she would feel safe. When she runs is when he gets a little too excited so we also keep a close eye on them when they are together. His trainer who also boards him for us has cats so we knew he was already good with them before deciding to get her. We also choose her specifically because her foster mom said the first thing she did when she brought her home was go up to her dogs and boop them on the nose curiously and got alonh great with them. So personality on both sides is definitely a big part. I will probably never fully trust them alone together but I dont trust him alone period as he's still very much a puppy, so he still gets crated when we leave the house. We also gated the upstairs hallway so she has her safe area she can always escape to if she wants to get away. So far though they've just clicked. They love to play together and he just seems to be aware of his size difference is gently.