Hannaford, ND is in Griggs County. I checked the out-of-print book titled, Adoption Agencies, Orphanages and Maternity Homes--An Historical Directory. The WorldCat data base lists 147 libraries in the U.S. (including one in North Dakota) that have copies of the Directory.
The Directory contains 40 entries for North Dakota, but none are in Griggs County. I have no opinion as to which institution would serve Griggs County.
Another directory you may wish to look at is catalogued as :
UNITED STATES. Bureau of the Census. Benevolent Institutions, 1910. Washington, D.C.: Govt. Print. Off., 1913. 411 p. Includes listings of individual institutions and societies for the protection of children, but no index.
You could check the North Dakota State Census of 1915, which is mentioned in a book titled, Search and Research, by Noel C. Stevenson. He says it lists names of family members but often omits their ages. In your case, you would have to skim all entries in the state until you find your mother and her siblings in hope the name and locale of the orphanage appears in the census.