Celia is an endearing character. Although it takes Minny a long time to realize it, Celia is like no white lady she's ever worked for. In a good way. Celia is a sharp contrast to women like Hilly and Elizabeth. She's a Marilyn-Monroe look-alike who wears tight skimpy clothes (probably something like this), much to the chagrin of the high-society ladies and much to the delight of their husbands.
Unlike those ladies, Celia wasn't born into high society. She's from Sugar Ditch, Mississippi, and was born and raised poor. Her marriage to Johnny Foote places her among Jackson's elite all of a sudden, but also right outside that circle. See, Johnny is Hilly's ex – you can imagine, then, how much Hilly likes Celia. Hilly's antagonism toward her is one thing that unites Celia and Minny.
Celia's biggest problem is that she believes she's only worthy of Johnny's love if she can give birth to children, but she's plagued by miscarriages. She comes to learn that her husband loves her for who she is, and that she can live a happy life even though people like Hilly and Elizabeth don't like her. After Celia saves Minny's life by warding off a violent, would-be rapist with a fireplace poker, Minny begins to see that there is a strong heart beneath the country exterior.