Maybe it's an idea to help your wife lessen her fear to sit and look at some really outstanding ball python sites online so she can see how very beautiful these snakes are, both normal and morph. We women do love something of beauty. Rather than focusing on the whole snake (which can be intimidating) just focus on it's scalation or something like that.
Also a few visits to a good pet store that has snakes might help. Just being around them, not even handling them at first, may help her feel more comfie before the snake you want to get arrives.
We've found with friends that are not comfortable with our snakes that if we point out the small details of beauty, muscles and movement it helps to focus away from the fear a bit. If we get one of the snakes out we control it's head area and just gently encourage them to simply touch it with one finger. Amazing how many people are enchanted and amazed that it's not "slimy". Also once they see our kids handling the snakes, most adults realize there's little or nothing to be afraid of in a ball python.
~~Joanna~~