The document I looked at, on Familysearch.org, shows Rosanna's name as Crippen. It could have been transcribed from something else, perhaps.

Found Robert and Rosanna in Erie County, Groton, 1850, by doing a search for Robert, born IOM, Erie County.
1850 Groton, Erie County, Ohio: Robert Loyed 23 blacksmith IOM; Rosanah A. 21 New York; Thomas 2 Ohio

Looked for a death for Rosanna, between 1850 and 1860, but didn't find.

Then we have George Brown and Mary in Oxford County: (I think I said Mary was the widow of John Brown, but pretty sure it was George, as this family seems to fit)
1860 Oxford, Erie County census: George Brown 42 England; Mary 41 England; Betsy 11 England; John 10 England; Fanny 7 England; Mary 5 England; Bessie 2 Ohio (This one should be Rosa, but try as I might, I can't make the census taker's scrawl look like Rosa or Rosie--not sure how to resolve this)

Looked for a death of George Brown between 1860 census and 1863, but didn't find

Marriage: Mary Ann Brown, Thomas Huntley, August 17, 1863, Erie County, Ohio

Here are the kids, in 1870, looks like living on their own
1870 Oxford census: John Brown 20 farm hand Ohio; Mary 16 England; Rosa 12 Ohio; Fanny 19 England

Haven't yet found Mary Ann. She should be there, and Thomas Huntley most probably died, if she married Robert in October 1870.

Marriage of John Brown and Isabella Lord October 5, 1870 in Oxford (Familysearch.org)