CBR grabbed an an interview with Greg Berlanti (producer of Arrow and The Flash TV shows) at PaleyFest 2014, and Berlanti confirmed the rumours that a 'Supergirl' TV series is actually in development.
The show is currently in the early stages of development however, and Berlanti says he was 'not allowed' to talk about any details of the project.
Berlanti said, 'we're just starting to work on it. We haven't gone to the networks yet, so. I'll be happy, very excited to talk about it once we know where its home will be and that kind of stuff, but not at this moment. '
CBR says that rumours of a 'Supergirl' TV series began to emerge at the beginning of September, with talk of Berlanti working alongside Ali Adler (producer of Chuck), as the pair had worked together previously on 'No Ordinary Family'. Chief Creative Officer at DC Entertainment, Geoff Johns, is also rumoured to have a part to play.
Earlier reports said the series was being pitched to networks, but as stated by Berlanti above, they're not even at a that stage yet.