The queen's hair was black as night; and the king's had been, and his daughter's was, golden as morning. But it was not this reflection on his hair that arrested him; it was the double use of the word light. For the king hated all witticisms, and punning especially. And besides, he could not tell whether the queen meant light-haired or light-heired; for why might she not aspirate her vowels when she was ex-asperated herself?
As the quote above indicates, the Queen still has black hair. We might presume she's quite a bit younger than the King, though still middle-aged. GMD has a tradition of having "attractive wise old women" as a character type, and while the Queen doesn't really fit this type (she's not that wise), we can certainly visuallize her as an older beauty. Certainly she's not meant to be a crone.
She's very nice, but she teases the King a lot. And whereas, he hates puns, she likes them a lot. We also gather that her accent is not quite "royal." In the game, the queen is friends with a hermit who was once a counselor, but who punned once too many times around the king. Apparently he helped design her garden (this isn't really in the story, except for the identity of the hermit).