Mary Ann Tatum (Underwood) - Maiden Name and Parents

This Mary Ann (Underwood) Tatum is connected to Godfrey parents instead of Underwood parents?

Aside from that, I've been researching the Tatum and Carlisle lines today and all the sources I've found on Nathaniel Tatum just list his wife as Ann and don't give her maiden name. I've been putting info in their profiles since most of them had nothing in them. One source is this:

https://www.ancestry.com/discoveryui-content/view/111104:49380?tid=...

which is one of the ones that mentions Nathaniel's wife as Ann and no maiden name is given.

So, I'm wondering what the documentation for her maiden name is and why if she's an Underwood she has parents with a different surname.

Thanks in advance for any additional information.