Yep, slight genetic variations.
Everything is good, it is not a problem, just a super happy and healthy plant.
I have had plants with 30cm+ leaf blades, or over one foot in length!
Don't worry, those big leaves are making bulk energy that will allow her to grow fast and large.
Pity it is an auto flower, she would be a prime phenotype and would have been well worth cloning!
Hope this helps, Organoman.