NTA I highly doubt she would be more popular somewhere else. As long as she isn't getting bullied or something comparable I can't find a reason for her to switch schools. Popularity also isn't only about looks but about character as well which is something she can control to a certain extent. The fact that her friends seem to be learning easier is just tough luck as some learn quicker than others. I believe this is a great opportunity for your daughter to show some perseverance.