Looking for any info on Amanda Margrette Andersen

My great-grandmother (on my mother's side) emigrated to the US in May 1900. I found the manifest of her ship, it was the S.S Hekla and it lists her as Amanda Abrahamsen which was her married name. She traveled with her baby who was only 6 months old named Agnes. The manifest lists her as being from 'Sandefjord', yet my mother (who was raised by her) said she never heard that name and thought her grandmother said it was 'Stavanger' from where she came. I looked on the digitalarkivet web page many times and I seem to have hit a brick wall. None of the Sandefjord documents I have looked at mentions anything about her. I know she made her confirmation on April 13th 1890, we know this for reasonable certainty because we have her bible which has that date in gilded letters on the front along with her name- she would have been 14 years old so that sounds about right. Yet the parish register for Sandefjord does not list her name among the confirmants for April 13th 1890, and there were pages and pages of young men and women who were indeed confirmed on that day. Could the manifest of the S.S Hekla be incorrect and she was not in fact from Sandefjord? I don't know anything else about her except she died in 1964, was listed in the 1910 census here in Brooklyn with her husband Hans and their children, and was the oldest of the eight Andersen children. Oh, and that prior to her marriage she worked as a domestic in the home where her minister lived. Would anyone suppose that, since I do not speak/read Norwegian, I have come to the end of the road in my search?