Dear JoelWhy, thank you for your input on this! I agree it would have to be luck, and if she was anyone else I would instantly dismiss this without a second thought. However, she is horribly accurate in everything - I learned quickly that even a slight exaggeration in a story renders the whole story wasted breath in her view. She prides herself on her accuracy and she happily says that she could never guess any other star sign and admits that even her guesses for Pisceans are wrong on occasion. But she would bet her life that her guesses are better than chance on Aquarians. Hence, why I wonder if there could be ANYTHING, that is not complete horsesh*t, that could even possibly, slightly, influence a person's personality?
I would be happy to leave it, but it is my main trump card! Albeit a dog-eared, palm-greased card considering the number of times I have played it now! 
I concede it's possible that a person's appearance would somehow, someway be influenced by the time of year they're born. But, I find it
highly unlikely. In fact, I believe that either she can pick out Aquarians through some supernatural power or she can't. (My money is on the latter option.)
If you really want to put this issue to rest, there's a simple way to do so. This type of "power" would likely be eligible for the JREF prize for $1,000,000. (In fact, Astrology is specifically mentioned by JREF as an eligible category.)
But, I would recommend starting off smaller. Set up an unscientific test with, say, 10 people (3 of whom are Aquarians.) Have her examine the 10 people and pick out the 3. I'm terrible at statistics, but I say if she gets even 2 out of the 3, I'd be impressed.
If she can do better than chance, you'll need to get some"media attention" to apply for the JREF prize. (Brian from
Skeptoid has been approved by JREF to fulfill the media requirement; he's willing to provide you with the requisite media attention if you can convince him of the power) You then get sign up for an informal test. Pass the test, you go to the formal test. Pass that, you get $1 million in cash w/in 10 days.
Of course, no one's ever made it past the informal test. I'll bet dollars to doughnuts your girlfriend doesn't even do better than chance on a self-run test with 10 people. But, if she genuinely believes her claim, I suspect you guys wouldn't mind the extra cash:)
That being said, if she gets past the informal test, make sure to marry her before the formal test. You wouldn't want her to dump you right before she hits paydirt!
