Dear Cynthia Dixon,
Thank you for posting your question to history hub.
It appears that you've been at this for some time and are well-versed in scouring various sources for information. However, the Federal Government does not ordinarily create or maintain birth, adoption, death, marriage or divorce records. Such records are made and kept by State and local governments rather than the National Archives. We suggest that you continue searching substitute record sources such as probate records, church records, and newspaper records that may uncover more information about your grandmother and possibly her parents.
If you haven't done so already, you might want to reach out to the state and county historical societies for the areas that you know your ancestor lived in. Also, if you come across anyone with military service, you may be able to research military personnel files and pension files which might lead you to the information you're looking for as they often list parents and/or designated beneficiaries.
We hope this information is helpful in your research!