We can agree that LFs plot is going to be found out and lead to his demise and given the Scooby Doo like writing lately, having the girls be on to it makes the most sense.
Arya has to at least be on to it, and is maybe testing Sansa but, if Tormund lives last night then there is zero chance of Stark on Stark violence.
My best guess is that this ends up mirroring Ned's bargain with LF coming back to bite him. Don't discount the Scooby Soo reveal by Bran to the Sisters about how that went down or what is going down.