Most nontechnical parents who see their son or daughter spending countless hours on a computer just think that he or she is wasting his or her time.
(That last sentence would be a good place for those mythical gender-neutral English pronouns.)
I definitely encountered that. The same parents who called me lazy for sitting in front of a computer from ages 14-18 are now quite happy with how things turned out--a day job with a high salary and a startup in the works lol. You never know what that kid could really be up to...!
However, I don't know that I agree that if people were encouraged the same that it would somehow make the balance 50/50 or even remotely close to that. Of course, my perspective is limited to personal experience.
I have a lot of geeky girls in my family and I know a lot of women who are geeks, and they've all been interested in other geeky pursuits - medicine, psychology, civil engineering, EE, chemistry; none of them have had a remote interest in software specifically. Why? Because it was too boring for them.
Maybe we should bring it on ourselves to make the work seem more interesting if we really want to try to bring some balance to the gender mix.
I don't know if I agree with her totally (I think the negative perception is more a conflation of IT with CS - people think CS is more about using Powerpoint than an intellectual pursuit) - but there is definitly a case for fixing the public perception of Computer Scientists.
I can easily imagine a society where 90%+ of the programmers are women, where programming is thought of as a typically female profession, requiring skills such as accuracy and conscientiousness.