Factual error: In one scene, Vada is showing off her mood ring. The movie is set in 1972 and mood rings were not created until 1975.
Factual error: The pirate ship ride was not invented until 1981; however, it appears at the carnival that is supposedly taking place in 1972.
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 ★