I'm pretty sure one of the 3Dream/Mairy hair which is longish has a pull back morph.  It's not exactly a ponytail but it might do what you want and this way you won't have to use two different hair props and try to match them up. 

IIRC it's the Bandua Hair http://www.daz3d.com/i/shop/itemdetails/?item=9364

You can hide the tiara and stars.