Yes, that's very helpful. I don't see any way that the Newsweek article mentioning an older sister is possible. But a younger sister is possible if they had more than five children. I don't remember if they did, and a younger daughter wouldn't show up on a census until the 1950 census is released in 2020.
The approximately four year gap between DE and JCE is unusual for that time unless there were miscarriages. But there wouldn't be time for a sister to be born, be molested by a precocious DE and die before the 1940 census. So I still think it's safe to discount the Newsweek statement at this point.
We have one four year gap, and a three year gap. Miscarriage and still births would have still, likely, been common. Still births were not recorded, nor were early infant deaths, if they passed between census dates, and, babies who lived only a few weeks, some times didn't get a stone/funeral. Family's had to feed the living, and move forward. The census also does not include children born on, or after, April 1, of 1940. The census date was May 1, 1940, which had instructions as to how they were to list the age for each person.
DE was listed as nine as of his last birthday. He was born in 1931. The highest grade he'd completed was 2nd grade. (So, it appears he was in 3rd grade at the time of the census. I don't have an actual birth date for DE but, again, I'm gonna take a guess and say June was his birth month.)
JCE was born 10/15/34 and was not yet attending school, and as of the census date, he'd have been 5 1/2 years old.
TE was born 07/14/37 so he was very close to three years old, 2 years, 10 months, as of the census date.
The twins were born 11/17/38, so they were closer to 1 1/2 years old.
That kind of puts them closer together except for the first and second child. The parents were married on 24th of December, 1929. So she had DE within the first two years of their marriage. My guess is June of 1931. I agree with your theory on possible other children. There very well could have even been a failed pregnancy before the first child, a pregnancy after the first child, and another after the twins (if the child were born on or after April 1, 1940, they'd not have been included in the 1940 census. They'd show up as a five, or ten, year old one of the next census.). I'm a bit tired, I hope that all made some sort of sense.