Many of the stories in Showcase 2 I'm reading for the first time. The "Mighty Maid" adventure has to be one of the most screwy stories in the book... If you ask me, Supergirl is a little too proficient at super-flirting, and at times has some curious private thoughts about Superman, eg. "His eyes are beautiful." And all that super-smooching... Well, as a plan, it ranks right up there with Superman's most nutty -- and what's with the Man of Steel calling Supergirl "Linda" when they're alone together??
The Superman/Supergirl relationship definitely took some strange turns during the Silver Age, didn't it? Probably the strangest of all is the story where Superman tells Supergirl that he could only marry a beautiful superwoman like her, but he's out of luck because Kryptonian law forbids marriage between cousins(!) So Kara searches space and finds her
exact adult double (named Luma Lynai, naturally), who Superman falls madly in love with! Of course, the romance is tragically cut short when Luma finds Earth's yellow sun would kill her.
This, I kid you not, is from the Supergirl story entitled "Superman's Super Courtship" from
Action #289 (June 1962) by Jerry Siegel and Jim Mooney: