Before the narrator has officially introduced readers to Osmond or Pansy, Madame Merle goes to visit them at Osmond’s villa in Florence. In an example of foreshadowing, Madame Merle tells Pansy that she will have a new mother one day, as seen in the following passage:
“Shall you miss mother Catherine?” she went on.
“Yes—when I think of her.”
“Try then not to think of her. Perhaps some day,” added Madame Merle, “you’ll have another mother.”
Here, Madame Merle hints at the fact that she has a plan (which she shares in the next scene with Osmond) for Osmond to marry Isabel, who she knows has just inherited a large amount of wealth after Mr. Touchett’s passing. As becomes clear over the course of the novel, their plan succeeds, with Isabel not only falling in love with Osmond and agreeing to marry him, but also developing a deep love for Pansy, whom she comes to see as a mother.
This moment is also a subtle example of verbal irony in that Madame Merle knows Pansy will not find a mother in Isabel because Madame Merle herself is Pansy’s real biological mother, a fact that Madame Merle and Osmond have hidden from Pansy her entire life.