skirt not easy

Today I made a skirt for my daughter. 

The problem was that she asked me to put elastic in the waist instead of a zipper.

I believe she asked this because I have always said I don't do zippers.  The pattern was a pleated skirt so I went up two sizes from her size and added a waist band. 


 The skirt is abut one size smaller since I left the zipper out and put in elastic.
Now I must find a way to fix the problem.

    This is a sheer fabric with a liner.  I am afraid that if I work the fabric much more it will develop a run.