Before Deckard Shaw was introduced to the Fast and the Furious mythos, we met his brother, Owen Shaw, (played by Luke Evans) in Fast & Furious 6, and The Fate of the Furious brought their mother, Magdalene Shaw, (played by Helen Mirren) into the fold.
It’s unclear if Owen and Magdalene would also appear in Hobbs and Shaw, though I could certainly imagine them making quick appearances similar to how they showed up in The Fate of the Furious.
Now apparently Universal Pictures is looking for an actress “28-39, in the mold of Kate Winslet” to play Deckard and Owen’s sister, Hattie Shaw, who is an MI-6 agent.
Owen and Deckard served in the Special Air Service and United Kingdom Special Forces, respectively, before they became mercenaries, so assuming that Hattie is indeed showing up and is working for MI-6, I would imagine there’s some friction between her and her siblings.