Does she still want to meet?

Can someone tell me what I should do? The girl and I are both in our late 20s. I met her a few weeks ago in school, and she agreed to come out and get together. This gal orginally said she was going to be free on Friday, so I asked her to go to lunch with me on that day of this week. However, she now said whether I could do Thursday since she will be free most of the day, but I have to work that day. I told her about this, and she hasn't replied. I do believe that she is intentionally not replying because I do know she is replying to other people's emails (those people whom I also know.) I don't know what she is thinking.