In touring several of the Ingalls family sites, I was under the impression that the health of family members, particularly Carrie, was permanently affected by "the long winter" (as described in the book by the same title.) It sounded like this may have even had some impact on the fact that none but Laura gave birth to children. Yet, in rereading the series, it seems that Carrie is described from early on as being weak and fragile. So perhaps it was a number of factors combined?
As a side note, I find it interesting that there are no biological descendants of Pa and Ma's immediate family...which really speaks to the harsh realities of living in that setting.
I was just at the homestead this summer... didn't pick up on the idea of Carrie's health being affected.
As you say, she was always described as being sickly, so I don't know that you can blame the winter for her childlessness. She did live to be pretty old, so she couldn't have been that badly affected.
Speaking of which, I wonder how much the childlessness was by choice as opposed to health. Or at least I'm sort of skeptical that the childlessness was caused by the conditions. The German side of my ancestors were in the Dakotas during that time and they had kids. Furthermore, the Ingalls girls all lived relatively long lives.
I have often wondered why Laura only had one child and Carrie and Grace never did. It seems pretty unusual for the time.
Here's another one from our visit that I thought interesting...
Almost no artifacts have survived from the original Ingalls family. Pa's fiddle. A couple dishes. Really not much. At one point, much of their belongings were stored in a room in a home they had just sold; they (Carrie?) were to move them out soon. When the items weren't moved in a timely manner, the new owners got rid of it all. I need to look back at exactly when this happened, but it was timed such that most of the family would have been no longer living, so it was a last chance to preserve items for the future. I shudder to think of it all being discarded.
Another interesting fact is what has become of the royalties from the Little House on the Prairie books. Laura Ingalls Wilder's will assigned the proceeds (to begin after the death of her daughter Rose Wilder Lane) from her literary estate to the library in the small town of Mansfield, Missouri. Lane died without a husband or children, and she willed her estate to a male friend. Which then passed on to his daughter. The library has seen very little money, and I think a lawsuit in the last several years ruled against the library.