Keying out green Screen where subject has some green on Clothing

Next time use a blue screen if the subject wears green.

It has no use to even start filming!

If you have a lot of difficult colors, or worse - transparant clothes for instance, I find it best to key on white. You will have no problems with the spill and with proper lightning you can easily remove the much brighter background.

Having a lightsource coming from behind the subject, towards the camera will also give nice sharp edges on the subject.

The art of keying is in the setup, not in post. The extra time spent in preparation will save you tenfold in postproduction - if reshooting is not an option, the best you can do is rotoscoping like @Mylenium said.

No, "Inside Masks" or other garbage mattes are of no use here. The green stripe needs to be completely masked by hand the old hard way for the simple reason that including it in the keyer would mess up the matte. Duplicate the layer, mask out a sufficient area at the bottom of the skirt and blend it in with the keyed section on the lower layer.

Mylenium