A MUM was left furious after her daughter was threatened with detention over the length of her skirt.... Tammy Humphrey's daughter returned from her first day back at school with a note saying she would be disciplined if she wore the same skirt again.... 2 Tammy Humphreys was outraged after her daughter was threatened with detention Credit: Tammy Humphreys/ Daily Post Wales The black skirt was deemed too short as it was above the knee-rather than being knee length as the school uniform rules s