wait, really? why do you think edmure already knows about her?
"I’ll leave you to enjoy your food. Singer, play for our guest whilst he eats. You know the song, I trust.""The one about the rain? Aye, my lord. I know it."
so this singers is tom of sevenstreams, he is a member of the brotherhood without banners, which stoneheart now leads. he’s been scouting through the riverlands, as an obvious spy for the brotherhood and his knowledge has led to coordinated attacks and ambushes of i think two frey parties. and jaime took a liking to him so he’s overheard heaps of lannister/frey meetings. a+ job.
so basically jaime left edmure and tom alone, and i’m 300% certain tom wouldnt sing the rains of castamere to him god he’s probably terrified as fuck of the bloody song and tom wouldnt try and cause some psychological downfall for my lil prince. so tom probably warned him about stoneheart, i’m not sure if there will be an attack on edmure’s moving party… it’s 400+ soldiers and stoneheart doesnt have that sort of power to DESTROY THEM so i think maybe she’s planning something, also brynden is hanging around but i think he’s up north oooh theories are the best right gfdi.