I believe I found your Grace Garlington. According to The Garlington Family History by Thesta Scogland, page 191, published 1976, a Grace Garlington is listed as being the daughter of Eugene Garlington who was born about 1872/1874. He married Lucy Blackmon. Scogland spells it with an "o" but that could be a typo or misspelling. Listed with Grace are two brothers Frank and Glenn. Nothing else is given on Grace, her brothers or mother.
Eugene is the son of John Louis Garlington Jr. who was born in 1852 in Georgia and died in 1919. He married Emma Allen who was bon in 1853. She died in 1823. John Louis Jr. is the son of John Louis (Lewis) Sr. and he was the fifth child of Joseph E. Garlington and Nancy Hull Crawley. They were from Halifax, VA and moved to Georgia in the early 1800s. They are my direct ancestors.
I hope this information is of help. It appears at first glance that this is the family you seek. Happy hunting.