Luis Alvarez/Getty ImagesI am an only child. Even though I’m a 43-year-old middle-aged woman with bills to pay, I will always be referred to as an only child. And that’s fine by me, even if wearing the “only child” label hasn’t always been easy.Unlike being an “eldest daughter,” which comes with plenty of relatable memes and a lot of sympathy and head nodding, there hasn’t been quite as much understanding for us only children. “Spoiled,” “privileged,” and “selfish” are often the labels we get.Then there’s the other side of the “I would never have an only child” narrative: the belief that we’re...