Yes - thank you.
So the question remains: did Sansa send a raven Royce, Little-finger - or?
We don’t know for sure, but I’m guessing Littlefinger. He’s the Lord Protector of the Vale until SweetRobin comes of age, so he controls the Vale’s armies.
Or perhaps Sansa is taking Littlefinger’s advice and asking for help from her great-uncle, the Blackfish. The episode 8 preview/trailer shows Brienne traveling to Riverrun, so maybe that’s her mission.