Don't overthink this stuff. She offered to let you see the dog, so if you want to see the dog, call her and say so. Stick to the one subject. If she has anything else on her mind, she'll call you. Besides only calling about the dog would mean you have gone dim. And at least it is something you have in common. A little non-pressurized communication isn't bad.
Look, I have no idea what is going in your w's head. I can see how a 52 y/o woman can be questioning her life. You know it too. All you can do at this point is to back off and let her navigate her own waters. And during that time, do what you want to do, i.e. rekindle an interest in an old hobby, learn about a new subject (away from this stuff), exercise, whatever. Find something to do.
Did you play a role in things going stale? We do have to look in the mirror. It takes two to Tango.
