At the end, Benjamin Mee takes his children to where he met their mother, he takes them through that day's encounter, where Benjamin worked up the nerve to talk to his future wife with "20 seconds of courage," asking her why such an amazing woman would talk to someone like him. His wife responds, "Why not?", echoing the reason why Benjamin bought the zoo in the first place.
In the memoir on which the film is based, Katherine remains a predominant character up until her death halfway through. In the film, however, her character is dead from the beginning and appears periodically as an apparition.