Here's the anthology: https://www.goodreads.com/book/show/6390031-the-improbable-adventures-of-sherlock-holmes

And here's the story (at what I assume was its original home? Although I guess she could've posted it there after it was published in print): http://www.intimations.org/fanfic/holmes/Commonplaces.html

It IS slashy, but sadly only in suggestion. TBH it's really an Irene Adler story. But who knows--I'm only halfway through the anthology and more H/W might appear.