Marge is the mother of the Simpson house.
She is about 34, has huge blue hair, and a massive overbite.
She is married to
Homer and is the mother of
Bart ,
Lisa &
Maggie .
Patty and Selma are her two older single sisters.
Marge is a dedicated housewife and generally optomistic about life.

Marge is the glue that hold the family together. Without her calming factor or attraction to order, the family would quickly turn to chaos. (well, MORE chaos)

Marge is a bit old fashioned and naive at times. She thrives on family life and strives for domestic traquility.
While not alwasys successful, it is just enough to offset Homer and Barts Hijinks.
As time goes on, she has become a little more cynical.
When Homer is up to something, she usually just doesn't even want to know about it.