What is the meaning of the following paragraph from "Roman Fever"?
"Yes; being the Slade's widow was a dullish business after that. In living up to such a husband all her [Alida's] faculties had been engaged; now she had only her daughter to live up to, for the son who seemed to have inherited his father's gifts had died suddenly in boyhood. She had fought through that agony because her husband was there, to be helped and to help; now, after the father's death, the thought of the boy had become unbearable."
This quote is important because of the insight it gives the reader into the life of Mrs. Slade and how she is struggling with the change in her social circumstances now that her husband has died. The previous paragraph to the one quoted in this question explores this further, as she reminisces on her life and what it was like, being married to such an important man in society as her husband:
She had always regarded herself (with a certain conjugal pride) as his equal in social gifts, as contributing her full share to the making of the exceptional couple they were: but the difference after his death was irremediable.
Note how this sentence introduces the massive contrast between her life and status as Mrs. Slade before her husband's death, and then after her husband's death, with the difference being described unequivocally as being "irremediable." Now, her life has become a "dullish business": without the former distractions and duties that were part of her identity, old griefs, such as the death of her son, are left free to surface and haunt her. For such a woman, who has spent the majority of her adult years "living up to" various people, having only her daughter to live up to is a very hard proposition to face. This background information is important because of the way that it reveals the kind of life that Mrs. Slade is struggling to lead and what she is trying to face. It also perhaps reveals her motivation at wanting to get even with Mrs. Ansley and reveal her truth at this point in her life.