This is beautiful. I always love characters who do their work quietly, barely noticed, and your Winky is perfect that way. And her observations - wow. I loved (well, no, I LOVED) this:
"She saw how he observed the other professors with a terrible look of longing in his eyes, like an elf who had been banished from its home but still watched its family from afar."
You revived Severus wonderfully - I love the little bit of epilogue there at the end, and it happily-ever-afterness. Lovely.