Right, she kept some receipts thinking she was smarter than everyone else by having a paper trail, but made sure to get rid of the gun and knife, made sure to make a phone call leaving a message after, and having a place to stay lined up... she never denied she was going on a trip, she just didn't count on Juan putting all her pieces together.
I have always thought part of why she slit his throat, and shot him was all in an attempt to "add" to the scene making it appear like it was more than one person, or more like a hired/experienced kill, and then the ninja story. She thought it out, she just isn't as smart as she thinks she is. Just my opinion