Tonguez
A suffusion of yellow
No, she is an MCU witch, which is more like a D&D sorcerer. Her magic is inherent. Doctor Strange is a D&D wizard - his magic is learned and completely different.
I dont think its been stated outright but Runaways indicates that Witch is a title used by Scorcerers. The Doctor Strange prelude comic, shows Tina Minoru (who is a Witch) being trained by the Ancient One. Indeed the villain of that comic is a scorcerer known as The Witch.