I can see how it might seem odd, but I think she has relevance. The most important aspect to winning a World Cup is the psychological aspect. Netball is intensely difficult psychologically, there is a lot of pressure, it is high paced so there is little ability to calm the nerves, you really just need to stay on top of them. The silver ferns handles the nerves really well in the last World Cup, and if you follow netball you will have seen many occasions where teams haven't quite handled the pressure, in big finals and semifinals. Same as rugby, but more obvious.
She is just part of a panel, each member will be bringing different insights so they don't all need to know the same stuff. I'm sure she isn't going to argue with ted on the finer points of rugby tactics.
apparently the selection panel for the English football team in the last World Cup was made up of a whole lot of random people outside the sport, even outside sport at all.