Hilly is a character in this novel who, from her earliest introduction, is clearly shown to be the vain and prejudiced individual that she is throughout the whole novel. Note the way that Aibileen introduces her when we first see Hilly at Aibileen's employee's house:
Miss Hilly got a round face and dark brown hair in the beehive. Her skin be olive colour, with freckles and no moles. She wear a lot of red plaid. And she getting heavy in the bottom. Today, since it's so hot, she wearing a red sleeveless dress with no waist to it. She one a those grown ladies that stilll dress like a little girl with big bows and maching hats and such. She aint no favourite.
As the novel continues we discover pertinent bits of her past that are relevant to the present of the novel, especially that help us to explain her animosity towards the woman that Minnie comes to work for. Hilly was going to marry Johnny until Celia came on the scene and stole him from her. This of course means that Hilly hates Celia with a passion and will never forgive her.