Margo, Edith, and Agnes are Gru's adopted daughters.
Margo is very untrusting of people, taking a long time to warm up to Gru, and also does not trust his minions to begin with. She is quite optimistic despite her difficulty trusting people, telling the girls that they will be happy with Gru eventually. When Gru goes after them when they are kidnapped by Vector, she is happy to see him but its still unsure whether to go back as he gave them away again, but encouraged Edith and Agnes to jump when Gru makes a heartfelt apology. She gives Gru a big hug when Gru finally kisses them goodnight, and says that she loves him, finally viewing him as a dad.
She has a sarcastic sense of humour and wit, shown especially when Gru says not to touch anything, to which she replies 'Uh huh, what about the floor?' and 'And what about the air?', and also when she mocks Grus accent.She also implies Gru is stupid when he wishes to sell cookies to Vector straight away, whereas they usually go alphabetically. She can quite judgemental and scrutinising, and is very mature for her apparent age. She sees through Gru's lies about his 'dog' and 'cousins', knowing that it isn't a real dog at all, and that his minions clearly aren't human, marking her as quite intelligent. She outsmarts Gru several times by threatening to cause him grief or bargaining with him to get her own way, one occasion where he refuses to read to them and she says they will disturb all night long. She does have a fun loving side, such as throwing toiler paper around Grus living room, and having pillow fights with her sisters, but her highly protective nature towards her younger sisters means she must act the adult often. Margo is very good at ballet, and enjoys it a lot.
Edith is an immature child and has a very dry sense of humour. She is also very clever and devious, with a mischievous attitude and she loves to annoy people. When Gru walks in on them throwing toilet paper around his living room she immediately places blame on one of his minions. She is a bit of a tomboy, she gives Miss Hattie a mud pie, and likes spooking her little sister Agnes when they pray at night about bugs laying eggs in their brains. She was also impressed by Gru and Vectors weapons thinking they were cool and liked the thought of sleeping in a bomb.
She does have a sweet side, and cares deeply for her sisters. She also shows a caring side for Gru, smiling happily when they give him their money jar to fund his rocket, and is initially the most joyful when Gru comes to rescue them off of Vectors wayward ship, despite the fact he gave them back to Miss Hattie and they didn't realize it was Dr. Nefario's doing.
Agnes, like her sisters, wished to be adopted by someone who cared about them. At first, Agnes is only one out of the three sisters to be excited to be adopted by Gru. She happily hugs his leg and plays games with him, whereas her sisters are gawping at Gru, their dream of the 'perfect parents' in tatters. She is unaware of Gru's own dislike of the whole adoption, her innocence prevailing. She is a very naive and innocent child, which is why Margo is so protective of her. She thinks Gru's dog is cute and chases after him, despite some protest from Margo.
Agnes trusted Gru deeply even though he was, at first, rather cold towards her and her sisters, asking to hold his hand and for him to read her stories. When Gru begins to become more of a parental figure to the girls, her trust in him deepens more. She is the main reason Gru begins to change his ways, her unconditional adoration of him regardless of how he treats her makes him realise what life is really about. She unwittingly sets his change in motion after Gru defends her at the Space Ship blaster game at the theme park after the attendant mocks her for not winning the game which upsets her. She is very good at ballet, better than Edith and almost as good as Margo, but lacking her poise. She is not a needy child but does depend on her older sister, Margo a lot. She often looks worried if Margo walks off ahead of her and runs after Margo, not wanting to be left behind. She also demands Gru fixes her disintegrated toy unicorn, and when she is upset at being mocked by the theme park attendant, she looks to Gru with teary eyes for support. When she doesn't get her way, she holds her breath and pretends to faint, and Margo implies she has done this numerous times before.
Agnes has a huge love of candy, wishing her new parents to have a house made of candy, and happily eats out of the pet food bowl Gru filled with candy. She also loves fluffy things, her famous phrase 'Its so fluffy I'm gonna die' has become a popular and fast growing internet Meme. Agnes particularly loves Unicorns and wanted to have one for a pet, unaware of the fact that Unicorns were not real creatures.