He-Ra

He-Ra is described on page 392 of volume 1 of He-Man and the Masters of the Universe: A Character Guide and World Compendium by Dark Horse Comics, published 23 May 2017.

She is credited as being introduced in 2008 in MOTU Classics.

She is described as being the daughter of He-Ro's son (making her the grand-daughter of He-Ro) and King Grayskull's daughter (making her the grand-daughter of King Grayskull).

She is described as an ancestor of the Twins of Power (referring to Adam and Adora who became He-Man and She-Ra) and she guarded the Power Sword.

In the Void she outsmarted King Hiss.

On the bottom of page 392 under He-Ro's section (2008 MOTU Classics) it also mentions:
 * Before he died, he deemed his friend D'Vann Grayskull worthy of wielding the Sword of He. He-Ro's spirit later revealed to He-Man and She-Ra that his son married King Grayskull and Veena's daughter, thus making He-Ro the twins' ancestor.

This established that she was also the grand-daughter of Veena, the first sorceress.

The 2012 DC MOTU COMICS notes further elaborate:
 * DC comics established He-Ro as the lone surviving son of King Grayskull and Queen Veena. This is a different canon interpretation than the MOTU Classics story, however.