That's the English text. In the German original (Wikipedia ), it says wer ist die schönste Frau (who is the most beautiful woman):

Sneewittchen aber wuchs heran, und als es sieben Jahr alt war, war es so schön, daß es selbst die Königin an Schönheit übertraf, und als diese ihren Spiegel fragte: „Spieglein, Spieglein an der Wand: wer ist die schönste Frau in dem ganzen Land?“ sagte der Spiegel: „Frau Königin, Ihr seyd die schönste hier, aber Sneewittchen ist noch tausendmal schöner als Ihr!“ Wie die Königin den Spiegel so sprechen hörte, ward sie blaß vor Neid, und von Stund an haßte sie das Sneewittchen, und wenn sie es ansah, und gedacht, daß durch seine Schuld sie nicht mehr die schönste auf der Welt sey, kehrte sich ihr das Herz herum. Da ließ ihr der Neid keine Ruhe, und sie rief einen Jäger und sagte zu ihm: „führ das Sneewittchen hinaus in den Wald an einen weiten abgelegenen Ort, da stichs todt, und zum Wahrzeichen bring mir seine Lunge und seine Leber mit, die will ich mit Salz kochen und essen.“

But Snow White grew up, and when she was seven years old she was so beautiful that she surpassed even the Queen in beauty, and when she asked her mirror, "Mirror, mirror on the wall, who is the most beautiful woman in all the land?" the mirror said, "Madam Queen, you are the most beautiful here, but Snow White is a thousand times more beautiful than you!" When the Queen heard the mirror speak thus, she turned pale with envy, and from that hour she hated Snow White, and when she looked at her, and thought that through his fault she was no longer the fairest in the world, her heart turned round. Then her envy left her no peace, and she called a huntsman, and said to him, "Take the Snow White out into the forest to a far-off place, there she will be killed, and as a token bring me ~~his~~ [her] lungs and liver, and I will boil them with salt and eat them."

In addition, the evil queen originally is the mother of Snow White.

fair in this context refers to paleness basically. though, it's often meant in the same way that someone today might say "she's thicc" and just mean "she's attractive" in a more general sense. fairness meant beauty to European high society at the time. aside from the obvious racial connotations, it also implies that she has spent very little time outdoors and has been free of disfiguring diseases, so high of status. it generally carries a lot of implications beyond just "white" and "clear skin". it captures everything that a European nobleman of the time would find attractive in one word.