Hmmm, there's not a whole lot more that she's been in! If you can track down the other three issues of Detective Comics (#861-863) that come after Elegy, they're worth reading, although the art is totally different and kind of disconcerting. She was introduced in 52 and the backstory is worth knowing, but the trouble there is that there is a WHOLE LOT of other stuff going on and there hasn't been a Batwoman-edit. So unless you're really focussed on reading everything, I wouldn't recommend it. The other thing I would recommend is The Question: Five Books of Blood - it's mostly a Renee book, but there is some great interaction between the two of them in it. And Renee is completely and totally awesome ANYWAY. :P