Silk suit construction: HELP!!

Okay, I am at a loss!  For the last three wks I have been working on a silk suit for my sister.  It's for a pageant so everything has to be perfect.  She has to stand in a pageant stance in it where one leg is out in front.  when she does this, there is a slight bunching at her hips.  The skirt is not tight in her hips at all, and if I let it out anymore, it isn't going to look right.  I'm trying to tell my mom that there isn't anything you can do because the fabric has no stretch it's just going to do that, but maybe I'm wrong...Anyone have any suggestions???  I don't think it looks bad...I just dont' know what to do.  I'm attaching a pic in case that helps:

Okay, this is probably not very helpful but I have always learned that when there are wrinkles/bunching, they typically point to the problem, so follow where they start/end and see if there is an adjustment that can be made. Is there a slit in the back of the dress or could there be?  That might reduce some of the pulling.  Also, while you work on the adjustments, have her wear the shoes she will have on in the pageant because they might make subtle changes to her stance or posture that you will want to account for.  Sorry I can't be of more help!  For what it's worth, that dress is absolutely gorgeous.  It looks great on her. 

Thank you!