From the opening of the play until the final scenes and particularly until George "kills" their son, Martha dominates the action. Elizabeth Taylor, playing the role of Martha in the movie version of the play, won an Academy Award for her performance. This role is a choice part for an actress, demanding a great deal of versatility and ability.
As the daughter of the president of the college, Martha automatically carries a certain amount of clout that accounts for the arrival of the young guests at such a late hour.
Basically Martha is a domineering, forceful, and earthy person. She best characterizes herself, when she refers to herself as an "earth mother" who constantly wants to get at "the meat of the matter." She freely sprinkles her speeches with curse words and obscene words, remarks, and gestures. She openly makes known her sexual attraction toward the youthful Nick and delights in the concept of the game "Hump the Hostess." During the course of drama, Martha virtually ignores the presence of Honey.
Martha delights in letting people know that George is a "flop," that he has not taken over the history department as she had expected (in fact, Martha uses the word flop to also apply to Nick when he can't make it in bed). Martha uses the fact that George has not lived up to her expectations as a reason to demean him. She also believes that George desires her to castigate him — that he married her partly for that reason.
Martha knows that she can push George only so far, and she recognizes that George is the only person who can satisfy her physically and emotionally. Even though she has enjoyed the humor of "Hump the Hostess" and her assumed reputation of sexual liberation, it is ultimately seen that Martha has not been promiscuous (if for no other reason than because the daughter of the president of the university should not be so indiscreet). In the narration of the birth and life of their child, Martha takes on an indulgent, maternal aspect that is almost "Madonna-like." We come to understand that she needs the illusion of being a mother. The illusion is so real now that she has revealed the "existence" of their child for the first time. In other words, she has allowed the world of illusion to intrude upon the world of reality.
Therefore, when George "Kills the Kid," Martha is truly frightened of the consequences, and she expresses her fear in terms of the nursery rhyme — she is afraid of the big bad wolf, or in other words, she is afraid of facing reality.
The abrasiveness, the domineering nature, and the strength that Martha had earlier demonstrated has now left her and we see her at the end of the drama as a person who needs pity and compassion.