I'm currently replaying WVM to remind myself of a few things, and in fact I had the following train of thought during the conversation between Ethan and Willow (on why their father only took him but not her). Willow doesn't know herself either, but suspects that it has something to do with "sons belong to their fathers". I have a different guess, and it's not really flattering to the father.
Both had some inclination or talent for sports fairly early on (volleyball for Willow and basketball for Ethan). We don't know how talented they were at the time they were separated, but I think it's fair to assume that both at least showed potential.
A potential thesis would be that the father had hopes that an athletic career for the siblings could fund his retirement. By Willow having a leg injury it was doubtful that she could continue to pursue an athletic career. Consequently, the father then took the last child who could develop her full potential and took him under his wing.
This situation can be spun even further: It is likely that Willow would have incurred further medical costs, late effects due to the accident. We do not know his financial situation, so we have to ask: Was the father unable or unwilling to support his daughter? Given the situation, we probably all agree that none of the answers are really satisfactory.
Both had some inclination or talent for sports fairly early on (volleyball for Willow and basketball for Ethan). We don't know how talented they were at the time they were separated, but I think it's fair to assume that both at least showed potential.
A potential thesis would be that the father had hopes that an athletic career for the siblings could fund his retirement. By Willow having a leg injury it was doubtful that she could continue to pursue an athletic career. Consequently, the father then took the last child who could develop her full potential and took him under his wing.
This situation can be spun even further: It is likely that Willow would have incurred further medical costs, late effects due to the accident. We do not know his financial situation, so we have to ask: Was the father unable or unwilling to support his daughter? Given the situation, we probably all agree that none of the answers are really satisfactory.