A case of the girl being too friendly ?

I got to know this girl when i was in my previous company and while i was interested in knowing more about her, i was about to quit and she was taking over my duties so i did not feel it was appropriate and i left it at that.

But a few months after i left, i started texting her and we started to chat more and more.

Her response has been pretty ok, she asks a LOT of questions about me and seems generally interested to keep the conversation going(our conversations can go on for hours). She has also initiated conversations a few times.

From what i observed while i was still in the company, she does not appear to be such a friendly person in public.

So after a few weeks of chatting and after she ask me about what type of movies i liked and me asking her back(she said she is ok with any type of movie), i decided to ask her out for a movie.

To be honest i was quite hopeful but to my surprise she said it was not a movie she is interested in watching and when i suggested another movie, she said she was busy with work and could not spare time to come out.

Although i do know that she is a bit of a workaholic ( eg. working at home on holidays), i am still skeptical on whether it is her subtle way to telling me that she is just trying to be friends and want me to leave it at that.

So is she interested or being just friendly?