With regard to Sleeping Beauty, you might want to point out that the princess is indeed described as beautiful, as it is one of the fairies's wishes that she "shall be the most beautiful woman in the world." In this fairy tale, beauty is indeed rewarded, as it is the...
With regard to Sleeping Beauty, you might want to point out that the princess is indeed described as beautiful, as it is one of the fairies's wishes that she "shall be the most beautiful woman in the world." In this fairy tale, beauty is indeed rewarded, as it is the reason why the prince falls in love with the princess when he finds her sleeping in the enchanted castle. She is described as "the fairest sight one ever beheld," which prompts the prince to kiss her. This breaks the evil spell, so you could argue that it was the princess's beauty, which helped the spell to be broken.
However, with regard to the second part of the statement, I would suggest you look a bit more closely at the text. You will see that the reason why the evil spell is put on the princess has nothing to do with her beauty. Instead, the evil fairy curses the princess when she feels aggrieved by the way she was treated by the princess's parents at the christening feast. Unlike the other fairies, she had not received a golden plate to eat from. Therefore, I would not agree with the statement that beauty is a danger in this story. The curse has nothing to do with the princess's beauty.
With regard to Snow White, on the other hand, I would suggest that you argue that the statement is true in its entirety. Snow White is described to be "as beautiful as the day." In fact, her beauty saves her life when the huntsman refuses to follow the queen's order to kill Snow White: "as she was so beautiful the huntsman had pity on her." It is also her beauty that makes the prince demand her coffin. He "saw the coffin on the mountain, and the beautiful Snow White within it." Again, it is thanks to her beauty that her life is saved: as the prince's servants carry the coffin away they stumble over a tree trunk, which causes Snow White to spit out the piece of apple that had poisoned her.
However, you can also see clearly that in this story it is indeed Snow White's beauty which causes all her suffering; the queen is jealous of the fact that Snow White is more beautiful than her. This is why she asks the huntsman to kill Snow White. She wants to remain the single most beautiful woman in the country. Therefore, in this story, beauty is definitely also portrayed as a source of danger and not just as a blessing.