Because you really can't have enough secrets for your big, bad nobility. By the way, the first 25 Westcrown nobility secrets can be found here.
26. Keeps old history books (meant to be burned).
27. Has an illegal printing press (and distributes pamphlets in secret).
28. Has committed rape.
29. Falsely accused another of a crime, leading to excruciations (public torture and execution).
30. Family hates each other more than anyone else and attack each other first (but in secret).
31. Male heirs must kill off all other male contenders in this family.
32. Females House members are expected to get pregnant to their relatives, to keep their bloodline pure.
33. The family is in debt.
34.The family has conspired against House Thrune during the revolution.
35. The intimidating Patriarch and his closest relatives are actually of a good alignment, simply pretending to be frightening to keep others from suspecting the truth.
36. The Patriarch's daughter is an aasimar who is encouraging her father to do good things.
37. The family is trying to kick off a war between Andoran and Cheliax because they have the ability to smuggle contraband into Westcrown in the event of a blockade.
38. There is a diluted amount of elf blood in the family but they consider themselves to be elves, politically, and wish to do all they can to forward elf goals.
39. One brother has married his other brother's woman and that has sparked a long-standing but hidden feud.
40. The Patriarch's heir isn't his son. It's the son of a Hellknight.
41. A family member has been killed and replaced by a disguised devil who hopes to manipulate the family in methods beneficial to the devil's superiors in Hell.
42. The family collects the ghosts of the dead relatives of other nobles so that they may learn their enemy's secrets.
43. A minor noble has great divination powers and has been using them to scry on her enemies but she lacks the political clout to get away with it if it becomes known to the other nobility.
44. An important nobleman is a closet homosexual and his / her spouse isn't aware of this.
45. A noblewoman has committed suicide six times and been resurrected at great expense by her husband each time. He isn't abusive, she's simply suicidally depressed. He would do anything to cure her depression.
46. A noble has grown obese due to his / her love of sweets and has to use a magical item to disguise his / her weight. If anyone found out about it, they would have a great blackmail tool.
47. A minor noble has had to dress his daughter as a boy in order to be able to continue his hereditary line. He's afraid, due to his illness, that he may pass on soon and without an heir his power and money would go to her husband's line.
48. After being bitten by a wild dog while hunting, a minor noble has begun to suspect that he has contracted lycanthropy. In truth, he is simply developing schizophrenia.
49. A poetic bard obsessed with love and loss is actually a sociopath incapable of emotion. While not actually a bad person, it would destroy his artistic credentials if he were found out.
50. A man is thought to be a violent abuser toward his wife but it turns out that she has a condition that makes her bruise and bleed easily. They maintain a charade because they fear that others would connive situations for her to get cuts and bruises if they knew how easy it would be.