First of all, if fourth graders are going to be distracted by their teacher’s looks… Armageddon is not far off.
Second of all, she’s beautiful. I don’t find her outfits vulgar, and she looks happy in what she’s wearing. If her outfits were a problem, the school’s administration would have taken care of it far before vicious people on the Internet got to her.
Live and let live. In other words, mind your own business. Have a great day!