Which bastards in Westeros were automatically legitimized once their parents married?

Question

I was watching a discussion between Elio and Linda, co-authors of The World of Ice and Fire and founders of Westeros.org, on Annullments in Westeros, in light of recent developments in the show.

Linda says in that video:

We do have an example of course from The World of Ice and Fire where children who were produced prior to marriage were rendered legitimate by the marriage.

I realized that I didn't know which example is she talking about?

Which bastards were rendered legitimate upon their parents marriage in Westerosi History?

Answer 1

Linda's referring to a detail from George's material that was cut from The World of Ice and Fire, but will be appearing in Fire and Blood, relating to a situation where Lord Hightower took up with his step-mother following his father's death.

The High Septon refused to countenance the relationship and would not allow them to marry, but they continued it and had a number of children. Eventually a new High Septon allowed the marriage and the children were rendered legitimate.