Woman in work only waves at me....

When I come into work in the morning my colleague (who starts earlier) will wave through her office window at me. She will only wave at me? Another colleague follows me in and she won't wave at him. I only work in a small company (under 15 employees) so we all know and talk to each other. Am I over thinking this that she could possibly like me? why would she only wave to me? I have thought before that she has a thing for my other colleague but she doesn't wave to him..
Woman in work only waves at me....
Post Opinion