I struggle with this one too. I think sitting still and focusing on what is being taught is not only respectful but to the child's benefit from a focus standpoint.
Ultimately, they need to learn to be still and be perceived to be focused completely on the speaker if they will ever have a real job.
Your not alone, but I don't think sending them to a school is the answer. A 7 year old can learn to be still later. As long as she is learning at pace with peers the other benefits of homeschool out weigh this issue.