So frustrated?

I posted yesterday, my sitter looked annoyed as I asked her if there was a particular reason she needed a certain day off. I said I would look and get back to her but didn't as I knew I was seeing her today. Just now I got a text saying 'I really need to know about this date now please.' I replied saying I was planning on just telling her when I saw her today but she did not reply. Yet again she is pissed at me, was I really in the wrong?