It is important to realize that ADHD is not always a "disorder," in spite of its name. It can be thought of as a collection of traits and tendencies that define a way of being in the world.
It is only when the negative traits associated with ADHD become disabling that ADHD requires treatment. Conversely, when treated properly, a person formerly disabled by ADHD symptoms can often control their ADHD so that it once again becomes simply a way of being in the world.
How both of you think about ADHD is actually very important. Having a "disorder" can suggest an illness that is perceived as "bad" and permanent. Thinking of ADHD as a series of traits that can be both positive and negative, and that can be managed with the right strategies, is far more likely to encourage optimism, effort, and patience.