A new Supergirl movie seems like kind of a no-brainer to me-- frankly even more than a new Superman. First, she's got all the powers and abilities of Supes, so you're not going to have a problem making the movie be action-packed and spectacular enough (which seems to be the main drawback with female superhero movies).
And second, she's a hot girl in a freakin mini skirt flying around kicking ass and shooting lasers out of her eyes!! That should appeal equally to both girls and guys, I would think.
Not to mention the fact it actually feels like kind of a fresh idea by this point (and something different from seeing yet ANOTHER buff dude in a leather superhero outfit). If it was done well, I think people would be all for that.
And second, she's a hot girl in a freakin mini skirt flying around kicking ass and shooting lasers out of her eyes!! That should appeal equally to both girls and guys, I would think.

Not to mention the fact it actually feels like kind of a fresh idea by this point (and something different from seeing yet ANOTHER buff dude in a leather superhero outfit). If it was done well, I think people would be all for that.