Miss Havisham’s behavior is not normal.
She never leaves the house, has stayed in her wedding dress since the day she was left at the altar, and her entire house is decaying.
[Everything] which ought to be white, had been white long ago, and had lost its luster, and was faded and yellow…. the bride within the bridal dress had withered like the dress, and like the flowers, and had no brightness left but the brightness of her sunken eyes. (ch 8, p. 40)
Miss Havisham was left at the altar by Compeyson, after he conspired with her half-brother Arthur to try to bilk her out of her fortune. She was so scarred by the experience that she shut herself inside the house for over a decade. She did not change out of her wedding dress, and let it yellow and decay. The wedding cake and decorations also remained. Nothing changed, as if time stopped the day she was betrayed.