this gal is not interested. If she is, she would say yes
immediately or if she is busy offer an alternate date/time.
She is trying to reject you gently and is taking the trouble to
nurse your pride. It is OK want. Happens to everyone. It is not
you, it is just that you are not her type.
Now move on. I think this girl have some tact, so there should not
be any fallout even though you are both working in the same
company.