Newbie Searching for Ancestors

Hello. I'm rather new to genealogy, and am searching for my great-grandmother, Susanah (or Susan) Hanson. She immigrated from Hammerfest with her family circa 1872, when she was ~12. I'm trying to find where Susanah crossed, but given the complex nature of Norwegian names at the time, and the fact that I have no idea what her parents' names might have been (other than possibly Hans?). I am coming up with so many possibilities that I feel stuck. I'd really appreciate it if someone more skilled could give me a direction- even suggest a strategy for searching the database here & knowing if/when I've found something useful. She is, so far, my most mysterious ancestor. The story is that after coming to America, Susanah became ill, and when she recovered, she found that her family had left her with an uncle (?), presumably to return to Norway. She worked as a servant until marrying my great-grandfather, Erastus St. John, in Minnesota, in 1877. My mother once asked her father if his mother ever taught him any Norwegian, and he replied that she didn't speak Norwegian. Mom always thought this was odd, but he died before she thought to ask for clarification. Now Mom wonders if Susanah wasn't Sami? The Sami were being persecuted around that time, as I understand it, and many fled. There is a strong family resemblance with some pictures we've found- one looks exactly like my brother! Not great evidence, but... it's all we have. I don't know if that possibility would change the search strategy, but there it is. Also, I'm an expat, living in Germany- so there is a possibility I might be able to take a trip to Hammerfest. I'd really love to know more about my ancestors before I do! Thanks so much in advance for any help anyone can lend.