1. Is it possible for your fence guy to put the new fence on top of the same retaining wall that the old fence is currently on? Personally, I could see where she might not be crazy about having a retaining wall that sits "unto itself" so to speak, with your fence on the other side of it.
2. Would you have any problem with her letting ivy or grape vines grow on her side of the new fence? Then her side wouldn't have to be painted and she could keep the Wrigley Field look.
I sense that there is much room for compromise here-neighbors who like each other can usually find a way. Perhaps others can think of some ideas also?????