The Hansen family emigrated from Denmark in 1864. They sailed on the General McClellan, and arrived in New York on 23 June 1864. In some sources Hansen is sometimes spelled as "Hanson." At some point the Hansen family changed the surname to Peterson.
Lena is actually the niece of Peter and Olene. On the ship passenger list her name is Nicholina, and on the company roster it is Nequiline. She went by Lena for most of her life. Her surname at death was Rowley.