I'll just say this so that it's quite clear. There is no such thing as love at first sight. There can be lust but not love. Love requires deep care which can only come with spending months with a person, not weeks, not days but months. Some people start their relationship based on lust and grow to love each other but that's different, no two people have ever started a relationship based on love from the get go as they first meet.
So what you are experiencing is simply lust (lust does not need to be physical, you can for example lust for power or lust for an idea) which is based on your positive preconceptions on her based on what knowledge you've gained about her. But this is about you and how you already know that your reaction is wrong. Not to worry though, it's perfectly natural and most (not all) people experience this in some shape or form at some point (mostly around the ages of 12 - 18 though) so you're not the exception but the rule.
Even the most logical and intellectual people can be controlled in ways they do not desire by some function of their brain. In your case at this moment it would be your case with this girl, in my case it would be my Cynophobia. Just count yourself lucky that while I'll go through the days fearing cute little puppies that I really should adore your problem will probably pass after a short while
