The events of Aisha's life have been distorted by time and people refusing to speak of it, leading to others inventing details (and likely, due to how the human brain tends towards confirmation bias, eventually believing it all). As per the events of "Time and Again", the rumors from "Crushed" are true, but only from a certain point of view.
- "I heard that she had a secret affair. And took off with someone." - Aisha left her family of the Clandestines to begin her love affair with her husband, Hasan.
- "I heard she had many affairs and she had a secret family." - As noted, she only had the one affair, with Hasan and Sana being her "secret family".
- "I heard she killed a man." - We see at the beginning of "Time and Again" that Aisha does kill a British soldier with a thrown knife, but in self-defense.
One might ask why Hasan didn't clarify the rumors after her death. What we see in the episode is that Aisha informed Hasan that someone (the Clandestines) are after her, and impresses upon him the need to leave. He can't be certain that the family is not still being pursued, so he likely attempted to stem the flow of information by simply not talking on the subject. Unfortunately, that just fueled the rumor mill.
Sana was very young at the time of her mother's death, so she probably retained fond feelings for her, but would be unlikely to have any real additional details others than the certainty that her mother was a good person, which means Muneeba was likely more influenced by the family rumors. Add to that that the vague disrepute of her grandmother likely reflected on her socially, and Muneeba is likely to simply shut the topic down as something she doesn't wish to speak of.