I personally think she thinks the Sirius/Remus shippers are amusing. I think her selecting the art that she did when she first start posting fansites on her webpage was just to tease us. XD You know, the one where Remus and Sirius are leaning all close like while working on the map and Remus has like his hand on Sirius' shoulder and they look all couple-y? Yeah, Jo pointing it out and saying she thought the artist had "good rendition" of the characters was her TOTALLY. TEASING. US.

*is so totally a S/R shipper*

Also, it's clear from statements she's made about Draco that she's very disturbed by the rapid Draco/Harry shipping. Or at least it makes her go "BUH? O.o"