As a teacher of young children, I generally suggest that parents not put their children in an all-day kindergarten class - it is SUCH a transition that it can be very overwhelming to the child, and cause behavioral and attention tending issues. That many hours of having to attend to work, the teacher, and activities is really pushing the limit of what is psychologically appropriate to throw at a 5 year old. Before enrolling her, I suggest you really do your research and know how the day is conducted - are there lots of outside breaks, potty breaks, snacks, and naptime? If they do not offer a nap at this all day kindergarten, do not enroll your child. As children, many of us went to all day kindergartens - myself included - but this was when kindergarten was far more focused on the needs of the child as opposed to pushing academics (we were offered two naps a day, plus two snacks and hot lunch, all offered and provided by the school itself). Kindergarten was originially created in order to socialize young children and expose them to what the rest of elementary school will be like - not to keep them there all day, expecting them to sit and be content with the monotony of an all day classroom. There is a reason why most kindergartens are early bird/late bird! No matter how mature you believe your child is, a full day at school will not help her gain more or better skills than she would at a normal, half day kindergarten - in fact, the sheer volume and number of hours placed upon her can often cause children to regress in terms of behavior and socialization.
If at all possible, I would try to enroll her in an early bird/late bird traditional kindergarten day. Unless the school she will be attending offers naptimes and lots of free play time, you should look elsewhere. I could go on and on - feel free to contact me with more questions or comments, I am both a teacher AND a child psychologist.
Good luck!