Scans_Daily

Actually in Gotham Central they do refer to it, with Renee's brother providing the exposition that they knew about Renee's orientation, they were just pretending to be a couple of appearances sake as Renee's parents, the GCPD and the neighbour she grew up in were crazy homophobic.

Basically her brother said she came out to him when she was like 15, but as pretended to date guys so not to upset her parents (who end up disowning her when she is forced out to the closet by Two-Face, so this wasn't exactly Renee being maliciously deceitful before anyone says).