If you have teenagers — or were once a teenager yourself — you’ve probably experienced this: Your kid’s jeans fit perfectly in September, but by December they’re showing ankle. The adolescent growth spurt can feel astonishingly fast, with…

If you have teenagers — or were once a teenager yourself — you’ve probably experienced this: Your kid’s jeans fit perfectly in September, but by December they’re showing ankle. The adolescent growth spurt can feel astonishingly fast, with…