Hotwheels Female Executive wants more Girls to be part of the Brand

not holding my breath that this has any better outcome than the last companies that tried it...

Hasbro tried the same thing with NERF, and whilst it didn't backfire, the "target audience" weren't appreciative of the branding/marketing. 

Provided that Mattel doesn't alienate girls/ladies in the same manner, the more the merrier! 

The only problem I see is that most younger girls, not all, but most girls don't care that much about toy cars unless they are the Exotic Supercars,which who doesn't like those.
I'll never understand why companies try to force them selves in to markets that ultimatly won't pan out, while making the core audience suffer through pointless marketing and weak gimmics. See the Halo franchise as an example.
If it gets more people into the hobby of collecting cars (racing them is a whole different level), then good. As H3zzard said, the more the marrier!

Not gonna lie, I have little sisters who have collections, albeit small ones, of their own, and who have shown interest in modding...

I had a girlfriend who was secretly into diecast cars back in 3rd grade.