I NEED HELP FAST!!!!

My daughter is 4 months pregnant and she is the maid of honor in my other daughters wedding that is on 6-14. She ordered a dress online and when she received it, it was the wrong size!!! After contacting the company they told her that they wouldn't have her size till 6-20. THATS NO HELP!!!! Does anyone know of a consignment shop, maternity shop...ANYWHERE that my daughter can get a solid blue or solid silver dress to wear in her sisters wedding????? She doesn't want to spend a small fortune for a dress that she will never wear again. Our backs are to the wall...anyone have any suggestions PLEASE????!!!!!??????