The way I did this was by creating an animation and having an oversized torus behind the head, brushing the hair through the torus and the shrinking the torus to the required size. It is a matter of timing it right to get the hair through the torus without it spilling everywhere. You might need to move the torus in the animation. Since I also wanted to suggest some movement it did take a couple of tries to get it the way I wanted it and it did look right although the parameters had nonsense values (and indeed hair would really never behave like that anyway) but it did look right.
I did experiment with a separate object to grow hair for the ponytail but the rest of the hair didn't look right.
As always there isn't just one solution. It all depends on your shot and your expectations.