Searching for Carrie Sophie Nicholson

I am trying to build a five-generation pedigree chart for my son, Robert D. Stinson. His maternal great-great-grandmother was born in Norway and I cannot find her and her parents using all the tools I have at hand so I am asking or help. The name of the person I am trying to find is Carrie Nicholson. She was born on 29 Jun 1859 in Christiana, Norway. I have seen her name written as Carrie Nicholson, Carrie Sophia Nicholson, Carry Nicholson, and Cary Nicholson. The person transcribing her marriage certificate to Charles L. Dunning in Cleveland, Ohio on 7 Feb 1885 actually wrote her name as Kerie Nikkelson. The US Census records showing Charles and Carrie list her date of immigration to the US as either 1880 or 1881 but I have been unable to find the actual ship. I would sincerely thank anyone who can point me into a direction that would get me out of the circular loop in which I now find myself.