Imogen is pronounced the same way here in the U.S. I think you're thinking of
Imogene which does sound a lot like
Emma Jean, but with an "i" sound at the beginning.
So in the U.K. you would use a long "i" sound on the end of
Coralie? Interesting. I wouldn't have known that. Thanks.
And your
Irene story is exactly what keeps me coming here to BtN. Fascinating.