Youth and Marriage troubles
Maria Elisabeth was known as Liesl in the family.
Maria Elisabeth was considered most beautiful out of all her sisters, so Maria Theresia had high hopes of marrying her off to a high king or prince. Even Louis XV considered marrying her, his grandson would eventually marry her younger sister Marie Antoinette. Marrying her off proved harder than thought as she was known for her sharp tongue. But smallpox stricked and ruined both her appearence and marital chances.
In her later life she also suffered overweight. Liesl never married, nor had she any children, putting an even higher pressure on her younger sisters to do so.