It's possible that we may have a common ancestor here, although the name is slightly different.
I have a "Hettie Nannie Allen" in my tree, born in 1887. She is the youngest daughter of John H. Allen.
John H. Allen - b. 1840. in Williamson Co., So. IL, son of Randall B. Allen.
Randall B. Allen - b. 1813 in Beaufort Co., NC, son of Frederic Freeman Allen.
Frederick Freeman Allen - b. 1787 (E. Coast of Ireland?), son of John Allen & Mary Davis.
Frederick and John Allen show up on the Beaufort Co. 1820 Federal census. Frederick moved to Williamson Co., So. IL at some point in the 1830s-1840s. Randall B. Allen, along with the rest of Frederick's children went with Frederick to So. Illinois and died there. (Randall died in Williamson Co.)
I can give you more details if you want to e-mail me. Do you have more information on this individual "Nettie Allen"? I only have a name - "Hettie Nannie Allen" and no information on a spouse. It is possible they are the same individual.