Maddison Marples-Macintosh

Maddison Marples-Macintosh (aka Maddy in ep 1, or Mad in Don't Go Breaking My Art and Kate the Great) is the star of the show.

Her father is Mac Macintosh and her mom is Mandii.

Madeline is what Kate Black calls her.

Maddy the Monkey is what she is called in Love Potion

Macintosh is what the coach calls her in Breaking Up is Hard 2 Do indicating that may be her true surname, and "Marples" (her mom's maiden name) might just be her middle name instead.