My amazing friend Rachel has dug through the census data from 1860. First, I was mis-reading Josephine's surname (I thought I might be)--it's Scovell. I will go back and change the previous posts. The rest of the information she gathered I will paste below. You're a peach, Rachel!
"There's a Josephine Scovell, age 17, listed with her family in Noblesville Township, Hamilton Co., IN in the 1860 census. Two households away is a Scott family with a 15-year-old daughter Lucy M.
"The 1860 census lists Milton (age 24) and Washington (age 28) Tharp in Bremer Co, Iowa. There's also a J. W. (age 27) in the household, which was headed by Jane Tharp, age 56. She was born in Kentucky but the "boys" were born in Indiana." (A later double-check revealed that Andrew Tharp, Jane's husband and Washington's father, was also listed in the 1860 census, age 56).