I have to second the advice regarding not buying her anything.
When I am in love with someone, I go for broke. Jewelry, plane tickets, vacations, expensive animals, and so forth. That doesn't even include issues like rent, bills, car work, and groceries.
When I was seeing someone and found out she and I were incompatible, I didn't pay for anything, and I ended the relationship within a day of my "discovery". No sense in wasting emotion, time, or money.
For the young woman I am with, I've already bought our "anniversary" gift several months in advance, as well as a few other tokens of my affection.
So, to sum it up, as MUSTANG_18 said, "don't buy her shit".