Ah yes. A very young and comely Ann Francis. Her character was childlike with innocence and was breathtakingly alluring, attractive and sensual as a result. Today the female characters are almost vulgar due to their aggressive, masculine attitudes. I don't want my leading lady to be able to beat me up.
I had not thought of it but that was part of why she was so alluring. and yes, sexy. Of course the fact that she was beautiful helped.
In just about all those old 1950s Sci-fi movies the professor has a beautiful daughter.