I have been digging around on my Uncle Eric Christofferson's side of the family again. Apparently I was previously unable to find the family of Frank Grain in the 1900 census but I finally tracked them down today by searching the first name of "Frank" and narrowing in on Seneca, Wood Co., where I believed they lived at the time. I was successful in finding them with a poor misspelling of their last name ("Gren"), and therefore I found more specific dates for their children including Frances Grain.
I also looked into Frances's sister Mary's husband Henry Tidmarsh, who immigrated from England in 1904. I checked the Ellis Island records and found him very quickly. He immigrated on the Carpathia and I thought this was really interesting, because he came only a year after her maiden voyage, and less than ten years later the Carpathia was involved in scooping Titanic survivors out of the Atlantic. Then, of course, it was sunk in 1918. So there's a cool little bit of history on a distantly related man.