Johansdotter Hannu, Maria Johanna, born 1860, emigrated to North America 1887

[Maria Moborg]

I'm looking for Maria Johanna Johansdotter Hannu, born in Päckilä (Bäckesta), on November 10, 1860, Hietaniemi parish, Sweden. She emigrated to North America in May 1887 and left her 2 year old son, Victor Artur Hannu, in Sweden.  
 
In June 1891 her sister Greta Erika Johansdotter Hannu (born on may 21,1871) went to North America with Maria Johannas son, Victor Artur Hannu, and I believe that they must have had known where Maria Johanna lived.
 
I have had no luck in tracking them down. They might have changed lastnames in marriages. The boy Victor Artur may have kept the last name Hannu.
 
Hope for help.