Hi, Gene,
About the birth dates; Zilpha's comes from her tombstone (findagrave.com) - which is not to say it's gospel. The other two are based on census records, which we all know are subject to question. And of course, twins do occasionally appear among the Batsons. As we continue to search, maybe we'll find more documents to help us.

I'll be in touch via your direct email, too.

Best.