A mommy asked and here is a partial list of consignment shops. Here is a list covering Philadelphia, Montgomery, Chester, and Delaware counties. I have personal experience with As They Grow*
As They Grow - 105 North Aberdeen Ave. Wayne, PA 19087 - 610.293.8190 *, they have a nice selection of name brands from casual to dressy clothes for kids. They also consign furniture(some of which looked brand new), baby/toddler room accessories, baby/toddler accessories, shoes, and toys.
Butterflies and Blossoms - 3 North Five Points Rd. West Chester, PA 19380 - 610.430.7601
The Children's Consignment Cottage - 843 Valley Forge Rd. Phoenixville, PA 19460-610.935.9778
The Children's Shop - 820 Glenbrook Ave. Bryn Mawr, PA - 610.525.4866
Kid's Closet Thrift - 436 N. Oak Ave. Clifton Heights, PA 19018 - 610.626.1827
Kid to Kid - 1244 Township Line Rd. Drexel Hill, PA 19026 - 610.446.2544
Little People's Consignment Store - 27 E State St. Media, PA 19063 - 610.565.1055
Worn Yesterday(Manayunk) - 4235 Main Street, Philadelphia, PA 19127 - 215.482.3316; featured on 6ABC News on April 3, 2009 website:http://www.wornyesterday.net/ Some of the items are brand new with tags, featured on Philadelphia magazine's Best of Philly 2003.
Yesterday's Child Consignment Shoppe - 22 W. Eagle Rd. Havertown, PA - 610.853.2727