i thought so too! i think that works, i think ree is a couple years younger so she'd definitely likely met him through mccarthy, the moronic brother of the 7 since he's around finn's age more than the other two youngest. lol, with the brood of over protective brothers i can see antics and shit going on with that first crush/first lust line between them. it's cannon that they made it their mission to be home if any boy came to visit ree and they succeeded in chasing one off so bad that they never spoke to ree again much less walked on the same side of the street as her. and she went to all girls catholic school so she wasn't in the public school system which could lend itself to maybe finn didn't KNOW they had a baby sister until one day she came in from school, in her uniform, and he was like OH WELL hello. (insert side eye from the younger three here. lmao) I DO LOVE A GOOD CONFLICT so i am here for the " do i keep my friend, what do i do? she's friends witht he EnEmY." and it's not at all! oh thank you! i worked on her and am still working on her so it's like she's always growing and changing. we can definitely work out some magic.