Cecillia Gray (often called Celia) is a character in Nanny Mcphee and the Big Bang (Nanny Mcphee Returns, in the United States and a Canada.). She appears to be around twelve, the same age as Norman Green. Celia arrives with her brother, Cyril, in a fancy black car. She is brought to the Green farm because of a war going on in her hometown, in which she needs to flee with her brother to avoid getting killed by bombs. Upon arrival at the Green farm, she is greeted by the children, Vincent, Megsie, and Norman. They are upset with the cousins for arriving early. Just like Cyril, Celia is very spoiled and has a bad attitude. She is the last to leave the car (she only even does so because she is forced to by the driver of the car) because she is afraid of stepping into the manure that surrounds the farm. She constantly insults her cousins along with her brother, and they get into a fight that results in far more worse things then stepping into the poo. The fight ends with the Green children grabbing Celia's brand-new clothes and throwing them into the manure, leaving them "ruined" and Celia has no choice but to kneel down to pick them out of the poop. But the war doesn't end there, and Miss Isabel Green (the mother of Norman, Vincent, and Megsie) is greeted at the door one night by Nanny Mcphee, who is there to tame the fighting children. Megsie is asked to share her bed with Celia, but when she refuses, she is forced to sleep with one of the farm animals to teach her a lesson. The next morning, Celia finds only "ugly" clothes in the closet holding the dresses she was given to wear, so instead changes into Miss Green's wedding dress, much to the anger of all the Green children, especially Megsie. The dress comes back to the house later covered in mud and manure stains. The Greens are angry at Celia. The next day holds more promise. When Nanny Mcphee finds that the farm's prized piglets are missing (the ones they need to fix a broken tractor and keep the farm), she sends the children on a mission to find and catch the piglets. In an attempt gm make it so Celia will bond with the Green children, she makes a game in which the children must chase the piglets up trees and underwater to catch them. When the children finally feel like giving up, Celia stays determined and comes up with an idea to catch the piglets, and all five of the children pitch in to catch them and bring them back, so the farm is saved. The children now are able to get along better. To celebrate, Isabel Green brings the children on a picnic. But bad news soon ruins the joyful day. A telegraph arrives notifying Isabel that Rory, her husband, that has been away for a while fighting a war, was killed in action. Cyril and Celia are especially supportive. Nornan senses that his father is still alive, and travels with Cyril to try and find out the truth. Celia helps Megsie distract Miss Green right before she signs a contract to sell the farm, one event including Celia screaming and throwing a fit over a "mouse" (there is no real mouse, this is just to distract Isabel). Finally, Cyril and Norman return home, reporting that Norman's father is only missing in action (meaning he's still alive, just missing). Everyone is overjoyed. Later, Celia helps the Green family diffuse a bomb. A bomb lands somehow on the property of the farm, and if it explodes, the farm and crops will be destroyed. Celia yells up instructions to Norman, who is on a stepladder cutting the wires. The farm is saved, thanks to Celia, and she becomes a hero. Since the children now love each other, it is time for Nanny Mcphee to leave, and Celia chases after her yelling for her to come back, along with the other children, but are greeted by a returning Rory. This means that Celia and her brother are soon to return home, which disappoints them, but, of course, they are still happy to return home.