Dragons naturally have long lifespans, hence their potential to get big af. They can live for around 300-500 years. Usually, the only thing that cuts them short is pack battles or duels, both of which tend to take place in a dragon's adolescence. Dragons are notoriously territorial and get into disputes very easily, so although it's possible to reach grand sizes, it's not common, cuz they kind of maul each other to death when they're teenagers.
In show canon, Ember would be about half this size. Where my verse is set, she'd be about 2/3 this size when she's dating Starlight. I put a mlp pony silhouette for reference. She'll get even bigger than this, though, because here she's only about 30-35 years old. To use a real life reference, she'd be about as tall as 2 cows stacked on top of each other, or Drogon's size in season 5 of GoT.