Reactivity is a really big issue with dogs right now. I've wrestled with it a bit, and can tell you some of what has worked with my dog. The relatively easy life a well loved dog has, has a downside, it's a life that can take away a dog's confidence because they aren't working to do anything for themselves. One of the gateways to helping a reactive dog is to build their sense of ability. Asking your dog to do things that initially they are uncomfortable about doing is a great start - like asking your dog to jump up on a bench at a park, and various other elevated surfaces they find scary, then rewarding with a high value treat. Seems like a small thing, but it's standard protocol for dog trainers working with reactive dogs to build them up. This worked wonders for my dog, and his confidence in dealing with scary situations shifted noticeably. It was kind of amazing.
Another way to curb reactivity is to limit affection for a time. Some dogs view unearned affection as weakness on the part of their human, and it actually makes them feel vulnerable and reactive when outside the home. They interpret the affection as a cue that they are in a leadership position and so on a walk they will bark at anything threatening thinking they have no one to advocate for them, and that they've been given the role of protector, which mentally they can't handle.
Working with Nancy at any kind of job will help her too. Even doing some simple tricks, things that she can work to figure out with you. That can lead her into a better mindset.
