I can't beleive this is still a matter of discussion. It's her. Case closed.
Actually, that doesn't seem to be true. It appears to be her (although some disagree), but even the site that initially suggested that it might be her admits that it isn't a positive identification. Memory Alpha claims it's her, but it's pointed out on her entry's Talk page that this is not a definitive identification. IMDb claims it's her, but you yourself say that IMDb can't be entirely trusted.
So at best it's a plausible but unconfirmed identification. You can't say "case closed" if you haven't proven the case beyond a reasonable doubt. We wouldn't know for certain unless Mrs. Rathgeb (nee Vetri) or someone else involved with the casting or production of "Assignment: Earth" confirmed it.
(And isn't it Anouk Aimée rather than Aimee Amouk?)