Thanks Tommy.
Seems I have to officially renounce my wife's Indian passport before I can apply for her OCI. She acquired Canadian citizenship in 2010 and never really looked back at her Indian passport. Now that I'm going through the motions of applying for OCI, I discovered that while my Indian passport has a cancelled stamp on it, her's does not :-(
Guess I have to clone myself and line-up at both 40 and 60 Gillingham

. Do I then have to wait for the renunciation certificate or will they stamp cancelled on her Indian passport and hand it back to me so I can then apply for OCI right away? As per the BLS website, even renunciation can take a minimum of 8 weeks!!