My favorite non-sense and probably not canon theory about Brienne’s mom was that she was related to the Reynes since we don’t know if Roger had kids. I like the idea of Brienne having a legacy from her mother’s side that she is re-claiming as well as being an heir to Tarth, Castamere, & a relative of the royal family. Plus, it would fit with Tywin’s legacy backfiring. The massacre he gained fame for wasn’t as successful as he thought and now that line will continue through his preferred heir.

(Cont.) Plus, it seems like a GRRM thing to do to have a family feud end in marriage and a sort of restorative moment. Also, it would further fit into Brienne being the YMB since she is also robbing Cersei of the idea of her father being this bloody, mighty lord that all feared and respected, except this is the second time enemy family members slipped past him. Ellyn tried to be a lasting Lady of the Rock and failed, so it would be the 2nd time Brienne’s ancestor had a failed love with Jaime’s ancestor.

I had this ask in my inbox I wanted to answer mostly because the idea of Brienne’s mom being a Reyne is so big brained I can’t even. I hope GRRM is out there somewhere listening.