I'm not sure if this would work but you could import both models and delete the hair off the kid and scale down the tails to fit the head, re-uwv map and export.That's the plan.
So far I've managed to cut the lekku's from the female model, remove the hair from the child model, and then combine the remains. It looks pretty good, but it's not joined as of yet or anything. I'm really running blind with this sort of stuff, and have no real idea on what I'm doing. Looks neat though. :P
http://img.photobucket.com/albums/v642/Silveredge9/twilek.jpg)
Well, I meant that the lekku only would be done more easily with texture editing, for the tails it is not that simple. :)
I will try to do this, I will probably use settoken's new method to get the tails to work.
Whatever works. You're welcome to give it a shot. :P