Bored...so heres a NWR situation

Theres a girl that works in my building. She does some work with my office but she works on a different floor. Whenever she is in my office she is always WINKING AT ME. w..t..f. I don't think this is 'normal' but one of my co-workers thinks shes just being bubbly and friendly. It's getting uncomfortable, but hillarious at the same time .