It really doesn't matter if the movie is over or not...
If she responds and tells you it is no longer playing, it actually give you a great opportunity to respond back.
You are over analyzing this.. The key here is to send out a feeler like she did to you. "Hey, I just wanted you to know"...
Do you see how good that was? It left you wondering if she was missing you or if she was just contacting you with something she thought she wanted to tell you... YOU had to fill in the blanks... The great thing about it was that it OPENED the door for back and forth.. That is all you need to do here... WITHOUT obvious pursuit..... Subtle.. see if she is curious for more.... it leaves the door open for both of you.. If she doesn't respond, then you are still in good shape.. If she does, then you go from there... Baby steps....
