Not a good idea. I'm a professional pet sitter and have seen cats get themselves into all kinds of trouble just in the course of a day. The most recent cat got herself stuck behind the dryer and we had to move it to get her out. They frequently spill their food and water too, sometimes leaving them with none. You need someone to check on your cat at the very least every other day. I prefer once a day myself.
I'd definitely have someone look in on her. As it's been said, they can get into all kinds of trouble and since she'll be distressed that you're gone, trouble's even more likely. Having a pet sitter seems to reassure them, in my experience.