Given the marriage announcement from 1858 that Marion found (which indicates that she was the daughter of a Henry A. Cargill in New York City), her family can be identified in the 1855 New York Census here.
The family, living in a stone house in New York City worth $10,000 (this was a mansion) included Henry A. Cargill, merchant, age 43 (i.e., born about 1812), native of NY; his wife Mary P., age 35 (i.e., born about 1820), native of TN, what looks to be Mary's brother James C. Hays (age 34, born in TN) and Mary's mother Sarah Hays (age 65, born in VA), as well as 7 children (Henrietta, age 19, born NY, Huma H., age 16, born TN, Ponola C., age 14, born MS, Andrew H., age 11, born MS, Kate M, age 7, born NY, Duncan, age 5, born NY, and Mary C, age 4, born NY). Of these, the one listed as "Huma H. Cargill" may be your Annie Hays Cargill.