That really was lovely... I hate to use the same words as other reviewers... but it was the first word that popped into my head as I finished reading... so it must be true. :-) While I am now an R/S shipper in my heart of hearts, I started out reading marauder era stories about the two of them in het pairings, so that feels equally natural to me as well... and I imagine they could have all used as much love in their lives as was possible during those trying times... I also think your depiction works really well to support canon as well as the fanon of R/S shippers. It's not about sexual orientation as much as it is just about love... maybe that's why we all think it's so "lovely" LOL.
I hit the "Validate" button without sending your letter first -- oops! But this was lovely. My only quibble was a "4th year" that seems to have slipped past the proofreading, as you didn't do it twice. Very nice!