She looked, and acted human, but was robotic.
Plate's body "aged", her early form made her look like she was Seven, then her other form looked like she was around Twelve to Thirteen. Her third form made her look like she was Sixteen. She later stopped it, and made her body look like it was in between the three forms.
Since she was actually robotic, her arm transformed into a cannon.
She also used a spear in combat, but she rebuilt it to be stronger (somehow with a scan from her eye/optic).
She wore a Dunce cap, as said, but she also wore two blue bows in her hair.
Her dress was blue, and her shoes (Her shoes looked like those pointy shoes you'd almost always see a teacher wearing), her shoes were black.
She wore a yellow bracelet on her right arm. (the bracelet looked normal, but it also looked like those bandanas)
On her dress, she looked like she was wearing one of those Karate belts, though it would always be flowing on one side. (The karate-belt like thing was also Yellow)
Her hair sometimes appeared Brown, or black.
Her eyes/optics are Blue.