In her childhood, Martha was the only one who was ever nice to the Grinch as he had a beard despite being only 8. She flirted with him by saying that she loved the color of red and green, then caressed his face with her hand.
This surprised The Grinch who decided to make a gift for her in reciprocation for her feelings to which he shared.
The next day, when the grinch presented his gift to Martha, the other classmates laughed and bullied him for shaving in an attempt to impress Martha.
Before Martha could defend him from the ridicule, he left in a rage and has lived on a mountain ever since and she had not seen him since, despite carrying the same feelings for him for many years.
As years passed by, Martha grew up to become a sultry and mature woman. She's also became a rival with Cindy's mom Betty Lou Who. Both who challenge to win the light decorating contest each year to which Martha wins each year (mostly due to Martha's monetary standing).
Later she's seen telling Cindy what she knew about The Grinch whom shes known since childhood, but also inadvertently confesses to having had a "crush" on him.
At the celebration, Martha is seen unimpressed by The Mayor's behavior. As Grinch arrives, she is seen watching him from the distance and cheering him, but hiding her feelings.
At the moment of Gift Pass On, Augustus takes the oportunity to propose to Martha, she was speechless that Augustus asked her to marry him wich makes her feel uneasy since she's in love with The Grinch. Before she answears the proposal, she is interrupted by The Grinch who starts ranting about the comercial and frivolous side of Christmas.
She decides to think about Augustus's proposal until the next day. By Christmas morning, Martha watches how Augustus publicly blames Cindy Lou for what happened, even if the blame was his.
When Lou defends Cindy, she listens Lou's speech about the true meaning of Christmas and is touched by it and realizes that Christmas is also about spending time with your loved ones.
By the end, Martha decide to call off the engagement and gives Augustus back the ring when the Grinch reforms after revealing her true feelings for The Grinch which makes The Grinch happy.
Later, she was last seen during the song "Welcome Christmas" and at The Grinch's home where he's cutting the feast and they both flirting for a while. It seem that they're in relationship after they smiles at each other before the movie was over.
Martha has long blonde hair, which was previously straight hair with two pony tails but became curly in adult and similar facial features a other whos. She's shown to wear a black and white shirt and skirt, with white gloves in her childhood.
Later on, she is shown to have matured into a curvy and arousing woman, with a robust chest, and alluring behind.
She wears a Santa Claus designed suit, with her front ends revealing her cleavage and a very short skirt line which barely covers her waist line. She is later seen in a tight red dress, exposing her built figure and wears a mistletoe pin in her hair.
She is later seen in her sleeping gown, that is white and light blue, with large sleeves and cloak.
- Even though she denies that she have feelings for The Grinch, she still does since childhood. Making her not afraid of The Grinch like Cindy Lou Who, due to caring about him too.
- Martha May have love rival, but she love The Grinch and doesn't return her feelings to Mayor Augustus after seeing that Augustus was being mean and selfish to The Grinch since childhood.
- Martha May returns The Grinch's feeling after saying that Red and Green is her favorite color on Christmas which it surprised The Grinch and decide to give her a gift until the next day he was making fun of when he shave himself, lost his temper and run away which it hurt Martha May when she feel bad for him since childhood.
- In delete scene, Martha May won the light concert every year because of The Mayor have feelings for her and don't want her to lose by Betty Lou Who. The other deleted scene is when the mayor ask her out on a date which she kindly refuse.
- When the Mayor proposed to her, she was stunned and was afraid, because she still love The Grinch and she knows that The Grinch still love her too. At the end, she call off the engagement and tell everybody include The Mayor that she's in love and love The Grinch which that makes The Grinch very happy.
- Martha was the first girlfriend of The Grinch and the love interest in this movie.
- Its unknown if she'll be back in How the Grinch Stole Christmas (2018), but if she does, it's great to see her again to be The Grinch's love interest once more.