This is my opinion, I don't consider myself a PUA but I'm not an AFC.
She seems to like you, like someone told me on a thread, the girl have a life so don't be pissed if she doesn't answer right away.
Also, she maybe didn't answer your txt because she read it but was too busy to answer right away (like if she's at work) and then because it was marked as read she didn't think about it (Happens to me sometimes).
Don't over-think about it. If I was you, I would txt her after her trip (1-2 days after she comes back). But like I said it's only my opinion, I would like to see other's too.
Good luck.