WHO'S THE BITCH NOW?!

I work with a girl who seems to embody several things I find annoying. For instance, she's tall, very tall, one might even suggest "statuesque". And she's friendly - but only to men, unless she needs something, so one might suggest "bitchy". Inexplicably, after months of ignoring me she has made it her business to be friendly with me and for some perverse reason I cannot allow it. For instance she seems to always compliment my dresses and when she does I'll say "oh this thing, I don't even like it, I just had nothing to wear today" or my new gold embroidered ballet flats that I love (well until that fucking dog I was sitting ate them) and I'll say "omg, these cheap things, they're garbage" as I sail out of the bathroom. When I pass her desk or see her in the pantry she always looks over and smiles and says hi and I usually just grumble something under my breath and keep walking. I feel like I am sticking up for all the women in the office that she snubs every time I throw a compliment back in her face. How sick is this? I don't know what it is, I just cannot fucking stand her.