The question of rarity becomes tricky concerning the pairings that are not popular but are not exactly rare either. For those pairings, I voted "I don't know" because they can go either way, depending on where you want the cutoff point to be. I did notice that some pairings that were in between before DH, such as Harry/Luna, became more scarce after DH, and some grew in popularity.

But I do think all femmeslash pairings are rare, simply because femmeslash in this fandom is rare.