Shirring Help

I'm making my daughter a top from the book Little Girls, Big Style.  The neck is shirred.  It is my first time trying shirring, and it's really fun.  BUT the neck of my shirt is much wider than in the book.  She could wear mine, but I really like the look of the one in the book better.  I've tried steaming it, as the book states that helps to draw up the elastic, but it didn't help.  I think mine is drawing up as it should, but somehow it's just stitching too loosely, if that makes any sense.  I'm guessing it's a stitch length and/or tension problem.  Any advice would be much appreciated as I reallyyyyy want to make her this shirt!

Hi!  Is there any chance you could post a picture so we could see exactly what the problem looks like?  I think that would help!