That said, you have to judge whether or not removing her from the academic and social world of first grade would be detrimental to her. First grade is a pivotal year in a child's academic life.
After discussing her present levels of learning and achievement with her teacher(s), you will surely gain a sense of the plausibility of her keeping up with her schoolwork while on this adventure. Most teachers are very helpful in assisting parents with this assignment, providing them with the academic materials they need, and offering to be of occasional assistance over the phone should the need arise.
This will be a positive experience, one that your daughter will remember and treasure all her life. Unless there are compelling academic, emotional or social reasons that prevent her from joining you, I would begin making plans for your family's big adventure. Drop me an email from the road.