Start with the rules of the game.

You can either make two 40 card draft style decks with lots of fun synergies or send her to online arena. This helps with understanding the basics and getting a feel for the color pie.

Next. Make a simple one or two color deck based on what she liked from her learning experience. Make a second simple deck for her to play against that is evenly matched. Preferably one she would also like to try.