Combination of good genetics, mindfulness to nutrition, and a good exercise routine.
As long as you’re not abusing drugs and alcohol, watching what you eat, exercising, and not staying overly stressed out, you can stay looking good for a long time.
That said this picture also has a filter, she has on makeup, the lighting is adjusted, and the angles are also favorable too, the point is I doubt she wakes up looking like this. She definitely looks good for her age though, but lighting and camera tricks make her look better.