“Does it make any sense that our girls in school are taught at a young age to keep their hair shoulder length and in a pony tail for modesty (to follow the מגן אברהם) Yet when they become an אשת איש ALL boundaries disappear!’
Actually, that happens even before they are married – as soon as they finish school and are in shidduchim, they no longer have to wear their hair in a pony tail.
That’s because the reason for the pony tail is that it’s a school rule and not because everyone follows the Magen Avraham. They also stop wearing school uniforms at the same time, for the same reason.
The school rule about pony tails is a relatively recent innovation altogether. And it bothers me when something becomes a style (or a school rule) and all of a sudden, people thinks it’s the halacha. The halacha doesn’t change because of the school rules.