Bengta Marie Andersdotter (know as Mary Betsy in America) was born on 12 March 1857 in Kristianstad, Sweden. She was the illegitimate daughter of Anna Marna Larsdotter and Jöns Andersson. Bengta grew up in difficult circumstances and had to work during most of her childhood to help provide for her family. Anna first heard about the restored gospel of Jesus Christ in 1864  and was baptized shortly thereafter. She met Isaac Carlson in her church branch in Sweden and fell in love. They were engaged to be married when she was fifteen. Isaac moved to Zion in 1872 and promised to wait for Bengta.

Bengta's father passed away when she was a baby and promised an inheritance to her once she turned 25. But, if Bengta got married she could receive the inheritance earlier. So, in order to receive the money, she married her mother's friend Ola Offeson in name only. After receiving her inheritance in 1877, Bengta immigrated to Utah with her younger sister Elna.

Bengta lived with her sister in Salt Lake for a time and then moved to Pleasant Grove. Her marriage to Ola was annulled and she finally married her childhood love, Isaac on 4 October 1877. Isaac, being a skilled carpenter and stonemason, built them a home on the base of Mount Timpanogas. It was in this home that they had ten children, eight of whom lived to adulthood. Mary was a loving and determined mother and wife. She died on 15 July 1936 in Pleasant Grove.