Ladies are usually happier not showing their bare legs (or their bare upper arms)
It is our experience that informal or casual portraits are the most fun for everyone. We have photographed families in jeans and white shirts; khaki and black; browns and blues; pastels; and many other combinations that work quite well. We love bare feet in portraits (on adults as well as children), and we have captured some wonderful family interaction with everyone casual, barefoot and comfortable! If you prefer a more formal portrait, it is still important to coordinate colors.