If this is the first design you're looking at, you're likely thinking "WTF did you do to her!?" the simplist answer is that in this continuity Maggie isn't related to Marge, instead it's Homer and Mindy. She's been made to resemble both parents more, hence the eyes and overbite. It's explained in more detail on the Bart concept so go look there.
For some reason I really like the way the shading came out, Her hair too. She can definately be told apart from lisa now.
What I've worked out for her personality and such is a little risky but I'll go with it anyway. It'll be seperate BTW.