Question: Is it ever said how Vada's mother died? Harry mentions she met Vada and lived a couple of days after her birth.
Question: Was there a specific reason why Dan Aykroyd and Macaulay Culkin never appeared onscreen together throughout the whole movie except after Thomas J's death?
Answer: Harry seemed to ignore Vada a lot of the time, would suspect her friends were included in him doing that also.
Chosen answer: Most likely because there was no reason for a scene of them together to tell the story. It is assumed that because Thomas and Vada are friends, that Harry has interacted with Thomas many times before. There could have been scenes filmed with the two actors together that was later cut from the final film. This often happens to quicken the film's pace, shorten the running time, etc.
Answer: She still died due to complications from childbirth, despite living another couple of days. Hence why Vada believes that she "killed" her mother. Jane Seymour, the third wife of Henry VIII, also died from complications, but she lived for two weeks after.
To add an additional example to your accurate answer, a condition like postpartum pre-eclampsia (extreme hypertension) can occur from a few days to six weeks after giving birth and is sometimes fatal.
raywest ★
It's explained by Harry to Shelly after their first date.