No, there's no discussion at all about Antigone's and Ismene's appearances in 'Antigone'. Sophocles [496 B.C.E.* - 406 B.C.E.] gives readers absolutely no clues as to the sisters' ages or looks. There isn't even a clue as to their exact ages or birth order. But readers may guess that Antigone is the elder sister because of being engaged to be married and because of the confidence with which she handles their interaction.
*Before the Christian Era