In The Great Giana Sisters, Maria is used as a second player option for the multiplayer mode. However, in Giana Sisters DS, she's notably absent. At the beginning of Giana Sisters: Twisted Dreams, she is pulled into the dream world and abducted by Gurglewocky. Giana follows her sister through the portal and sees Gurglewocky eat Maria whole. Inside Gurglewocky's bowel, she met a passive owl, which will help her to find the diamond for going home. Upon finding it, she get captured by tentacles, preventing her to leave by herself with the owl. The owl later meet her sister, Giana, which explains what happened to Maria. Giana went looking for the red dragon. In the lair beneath the dragon keep, Giana defeats the dragon and retrieves her sister from the depths of Gurglewocky's bowels and returning home with their diamonds.
Maria is identical to Giana, but with different color scheme. She has short green hair, just reaching her shoulders. She wears a pink dress with a white under-dress, a red belt and wears red wrist bands. She wears white and magenta shoes.
As of the Dream Runners Storybook and the Owltimate Edition, she is now taller than Giana and has a ponytail with a green node.
In her Steam trading card, she has Punk Giana's clothes but with a different color scheme. She wears a sweater with a variety of red stockings and a blue skirt with a skull. She has black and red-magenta shoes. Her ponytail is bigger and her node is red and bigger too. However, that design is probably her punk form, since she use the same style as Punk Giana. Or maybe it's a redesign planned for the future.
Maria has a lot of commonalities with her sister Giana, though it's not officially made clear. Like her sister, she's courageous, has shown in two cutscene from the Owltimate Edition when she saved a owl and tried to escape Gurglewocky's belly.
Maria also cares a lot about Giana. She even protected her from their father.
Giana : Maria's sister. Not much known about their relationship, other than they care about each other a lot. In Twisted Dreams, Maria was saved by Giana from Gurglewocky.
Giana's Father : Not much known about their relationship either. However, Maria protects Giana when he's abusive to them.
Unlike Giana, she doesn't have any abilities.
In Giana Sisters: Twisted Dreams, Giana and Maria are both voiced by Katie Leigh, who is famous for voicing cartoon characters.
Maria is one of the character to have a lot of different designs, without counting Giana's concept arts for Giana Sisters 2.
Punk Maria? (Probably a redesign for her Cute form that was made after Twisted Dreams release. Surprisingly it wasn't added in the Owltimate Edition).
Maria in the ending
Maria in a cutscene from the Owltimate Edition.
Giana and Maria with their diamonds (without background).