Who is Mrs. Holton from Elijah of Buxton and what is their importance?

Mrs. Holton is the only member of the Elgin settlement to have arrived with money. The money allows Mrs. Holton to hire Mr. Leroy to assist in building her home, a home she will share with her two daughters, while waiting for her husband to join them. Mr. Holton continues to be held in slavery in Virginia. After hearing her husband has been killed, Mrs. Holton gives the rest of her money to Mr. Leroy to help with the purchase of his family.