Since this question was asked, I finally caught up with my almost 60 year-old sister who teaches 5th grade (10–11 yr. olds) at a public school in Virginia. Here is her response.
She can only share what is worn at her school. Times have changed since we were gradeschool age. Teachers rarely sit behind a desk in the front of room. They are roaming about and often kneel next to a desk when a student needs guidance. There are more group activities, and they often involve sitting on a carpeted area on the floor. During recess, many of the teachers play games with the students.
What do they wear? She said that many of the male teachers wear shorts and a t-shirt. A few women do as well. Some wear dressier clothes, but no one wears anything like a suit. The reason is that their clothes are often ruined through physical activity. This included playing part-time janitor in order to keep the classrooms and the teacher’s lounge clean.
She also mentioned that children this age love to touch their teachers. Because of this, she tends to wear tops with sleeves and either trousers or cropped pants. On the rare occasion, she wears jeans, but it depends upon the day’s schedule and her mood. Other teachers wear them more frequently.
Does it negatively impact their respect level? She said, “No.” When it comes to the children at that age, they aren’t bothered. As far as she is aware, no parent has mentioned it either. However, they are very vocal about how their child is treated in their eyes. Teachers in her school spend a tremendous amount of time documenting everything; much more than they had to when we were growing up.