Likewise, The Last Kingdom TV show covers these characters probably even more - Æthelflæd is in all 5 seasons [1] (although season 5 isn't out yet), and there's a lot of focus on Mercia.

[1] https://the-last-kingdom.fandom.com/wiki/%C3%86thelfl%C3%A6d

Edit: Should have hit refresh rather than browse tabs opened a while ago...err, I agree with dave333

Unfortunately that show has some odd changes to history done for the purpose of entertainment. Particularly on her character, and the history of Mercia and its relationships.

Yeah, there's all sorts of stuff they've apparently moved around, even from the books it was based on, which themselves were 'historical fiction'.

Many of the plots are true, but of different characters or different locations.

As does the show "The Last Kingdom."

The books are so much better; big fan of Cornwell.