Queen Stephe is very similar to Steve in appearance, with the same skin tone, general shapes and features, but appears to be wearing blush. Her garb is also very common of that of a female. Otherwise, Queen Stephe is completely indistinguishable from Steve. She's the only member of the Royal Family to be a Minecraftian.
Appearance in "Castle Royale"
This is Queen Stephe's only appearance in SMG4's bloopers. Mario initially believed she was Steve made-up when he saw her for first, but he later realized his mistake when he saw Steve and her in the same room. The Queen then realized herself too that she got mistaken for someone else, and angered chased the red plumber and Toad who was in the same room and said that she was a "b*tch".
Her name is a pun on Steve's, constructed to trick the audience (and Mario) into thinking she's another of Steve's crazy alter-egos.
She is the only other Minecraft character (obviously excluding Steve and his various alternate identities) in the SM64 universe, and the only truly confirmed female Minecraft character.
She's an exception in the Royal Family. She's the only female, the other members, her husband King Wooptedoo and her son Prince Big Whoop, being males, and she's a Minecraftian, while the other members appear as Mario palette swaps of Super Mario 64. She also appears to be partially mute, as Steve was in the oldest bloopers that feature him.