I may not be a supporter of the theory that Minerva is Satella's or Emilia's mother, but I found something interesting in the context of legends that may lead to the truth of this theory.

4. Minerva and the Daughter of Shadow

There is a little-known legend (partially derived from later Roman literature) in which Minerva is said to have created a mysterious being—the Daughter of Shadow.

Unable to create a child in a human way, Minerva is said to have sculpted a girl from marble and breathed life into her.
The girl was perfect in every way—too perfect. People began to fear her superhuman intelligence and the fact that she lacked emotions.
In the end, Minerva decided that the world was not ready for her creation and turned her into a shadow, one that appears only when someone approaches the boundary of true knowledge.