Allentwown Sewing Machine Outlet has fabric, At Piece Quiltery is in Easton (These two would be closest), and there is Pocono Sew & Vac and American Ribbon Outlet in Stroudsburg. There's also a small shop in Effort (can't remember the name)
There is also a Joann's in Allentown and a Hobby Lobby that is on the way to At Piece.