Melanie
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Melanie is the only daughter of Michael, approximately age 10. She is unable to live on Terra due to her inability to breathe in high-pressure atmospheres, a genetic trait handed down by her father. Although we don't know who the mother is, we have a pretty good idea that she died at the hands of the Eastern Alliance. (Greetings from Earth)
Portrayed by Gillian Greene
Notes
Gillian Greene was the daughter of Lorne Greene by second marriage. (Apparently, Glen Larson didn't have one of his own children fill the spot...)