I personally see many of the New 52 stories taking place in a multitude of certain time periods to make sense out of it. However, given crossovers and seeing things like Batgirl Babs alongside four Robins and the TimKonCassie Teen Titans generation in the

I do kind of have something like this in my brain, it’s total braincanon, not anything official. But it seems to me the current Batgirl happens before my version, and then eventually, Oracle and Birds of Prey happen. 

Which is all mixed up from how it is supposed to be, but makes a lot more sense to me.