A couple of other things have come to mind which might be useful. I assume you have Melanie B.'s birth certificate which shows she was born in Chippenham, Wilts, in the June quarter 1949. Mother's name Gomez, Ref: 7c 547. This means they were definitely in England at that date - quite probably half way through 1948. Even if they married in 1941-2, it is unlikely that they returned to England before 1945 because of wartime conditions. As George was in the British Army he may well have returned on a troop-sip with Irene following later. I do not think that troop-ships had "ordinary" passenger lists - the names of people carried would probably have been held by the Army authorities. If they came separately, Irene may well have come in 1947-8. After India gained independence in 1947 all people claiming British citizenship were given the chance of repatriation to GB which led to a flood of Anglo-Indians/coloured/mixed race people claiming their British citizenship as they felt they would not be welcome in an "Indian" India!. This would tie in well with Melanie's birth-date of 1949.
There is one other thing. You have posted on the East India Company board which deals with the actual EIC history. You might get some more helpful response if you posted on the Locations board for UK and Ireland - Historical British Empire.
Hope these musings are of some help.