Great Expectations

10-year-old Finnegan "Finn" Bell is playing on a beach in the Gulf Coast when an escaped convict suddenly pops out of the water and overpowers him, making Finn promise to bring back food, medicine and bolt cutters to get the iron shackles off his leg. Finn complies, and the convict unexpectedly tries to make Finn take him by boat to Mexico. The police seize the small boat heading out to sea. The convict hides on a buoy, and Finn's boat is towed back to shore. The next day, Finn sees on the news that the convict, mobster Arthur Lustig, had escaped from death row, but was recaptured and would face execution soon.
Finn's uncle Joe Gargery is called to Paradiso Perduto ("lost paradise"), home of the richest woman in Florida, Mrs. Nora Dinsmoor. She is a local mystery, having shunned virtually all human contact since she was left at the altar several years before. She ostensibly asks him there to do a gardening job, but instead she slips him a large sum of money under the door, calling it "gas money". Meanwhile, Finn, who he brought along, meets Mrs. Dinsmoor's young niece Estella in the overgrown garden. Mrs. Dinsmoor sees them interacting and calls Maggie (Kim Dickens), Finn's sister, to ask her to let Finn be a playmate for Estella, even though Estella apparently dislikes him.
On Finn's first visit, she is disappointed when the boy cannot dance for her, but is intrigued when he says he can draw. She forces Estella to sit for a portrait, which Finn draws with make up on an old piece of wallpaper. While he draws, Mrs. Dinsmoor warns Finn that he will fall in love with Estella and have his heart broken. After the portrait session, Mrs. Dinsmoor calls it a day and asks Estella to help Finn find the door. On the way out, she pauses to take a drink from a water fountain and politely offers him a drink from it as well. While Finn is drinking, Estella kisses him.
Several years pass. Maggie runs away from home and Joe raises Finn alone. Finn goes to Paradiso Perduto every Saturday, where he learns to dance with Estella. One day, Estella mentions that she has a party to attend. Mrs. Dinsmoor is shocked that she does not have an escort to take her, so Finn volunteers to escort her. When Finn shows up at the party, he is not allowed in because he is not on the guest list. Estella shows up beside his pick-up truck and asks him playfully if he will take her to his house. Once they get there, Estella starts to seduce Finn, only to suddenly leave, claiming that she is very busy that night.
The next day, Finn goes to Paradiso Perduto, only to be told by Mrs. Dinsmoor that Estella had left to study abroad in Europe. For the next seven years he resolutely puts Estella and Mrs. Dinsmoor out of his mind, and gives up drawing.
One day, a lawyer comes to Finn and tells him that he will have a gallery show in New York City. In the end, Finn is convinced to go to New York, which Estella had once claimed was the art capital of the world. When he arrives, he immediately gets to work drawing again, since he has no pieces to put on exhibit. He takes a break to get a drink from a water fountain - where Estella appears and kisses him. She then invites him to afternoon tea with her at a high class club.
Finn arrives to tea with Estella and some of her friends and fiancÃ©, Walter Plane, make fun of him by asking how much he would charge to draw a portrait of Estella. Finn leaves in a hurry amid the laughter of Estella's friends.
One day, Finn wakes up in his hotel room to see Estella standing next to him, reminding him that he had wanted to draw a portrait of her. While he prepares his sketch pad and charcoal, Estella takes off her clothes. After posing for a few sketches, Estella suddenly puts her clothes back on and leaves, saying that she is very busy. Growing sick of Estella's games, Finn chases her out to a cab and asks why she is so cruel to him. Estella sadly explains that she was trained to act this way by her Aunt Dinsmoor.
Walter shows up at Finn's hotel room one day, wanting to see the result of the portrait session. He then confesses to Finn that he thinks Estella is using Finn to push Walter into asking her to marry him and asks him how to please her. Finn has no idea how to respond, and Walter soon leaves.
The lawyer who had found Finn in Florida shows up again, moving Finn to a big studio where he can work on his art more comfortably. Finn quickly fills up the studio with his artwork as the opening date of his gallery draws nearer. He makes Estella say that she will be there.
One night, at an important event, Finn becomes frustrated when Walter draws Estella away when he barely even got to talk to her. He follows them to their dinner at a Vietnamese restaurant. As the bemused dinner guests look on, Finn asks Estella to dance. They dance for a few seconds and then leave the restaurant. Once on the sidewalk, they run for Finn's art studio, where they make passionate love.
Finally, the opening night of Finn's gallery show arrives. He looks everywhere for Estella but she is nowhere to be seen. Instead, Uncle Joe shows up, to Finn's surprise and, to some degree, embarrassment. When Joe accidentally knocks a tray of wine glasses over and tries to clean up the mess, Finn repeatedly tells him with increasing volume to "just leave it." Joe feels that he and his homely manners are an embarrassment to Finn and decides to leave early, despite Finn's attempts to get him to stay. Finn then goes to Estella's abode in New York, hoping to find her there, but instead he finds Mrs. Dinsmoor, who had come up to New York for the "special event": Estella's wedding. When Finn becomes upset at this news, she says icily that she warned him when he was a child. At this, Finn tells Mrs. Dinsmoor that she has broken his heart, the way her fiancÃ© did to her all those years ago. Suddenly remorseful, Mrs. Dinsmoor apologizes.
Finn returns to his studio to find a strange bearded man wanting to see him: It is none other than Arthur Lustig. Finn is at first incredulous, but then he becomes uncomfortable with the old man's presence and implies that he should leave. As Lustig is walking out the door, his off-hand comments make Finn aware that he has in fact been Finn's benefactor during Finn's entire time in New York. Finn thus accompanies Lustig to the subway station because Lustig has a plane to catch from the John F. Kennedy International Airport for Paris.
While they are waiting for a train, Lustig sees some unsavory acquaintances on the opposite platform. Finn and Lustig outmaneuver them and get on a train. They think they are safe, but as the train is in motion one of the old men comes through the car and brutally stabs Lustig in the side, stepping off the train at the next stop. As Lustig bleeds to death in Finn's arms, he reveals that he has been Finn's benefactor in return for the kindness Finn showed him as a child.
Devastated, Finn detaches himself from everything and goes to Paris to study art. He becomes successful in his own right, and eventually returns to Florida to visit his Uncle Joe and reconciles with him. Mrs. Dinsmoor has since died, but he decides to visit her house anyway. As he is sitting in the garden, he thinks he sees the apparition of Estella as a child. He follows the little girl through to the back dock where he finds the child's mother, who turns out to be Estella, who has since divorced, and whose life has gone downhill. She admits that she has often thought of him, and asks for his forgiveness for her past cruelty. Finn forgives her completely, and they hold hands and look out over the sea.

Question: What does she call the money that she slips under the door to Joe Gargery
Answer: She calls it the gas money