'Divine powers, huh? That's a bit of a headache to deal with. Why the hell should I fight a battle of attrition with this amateur half-god? I'll just butcher him.'
Marina switched tactics, realizing Eren's divine powers were on par with her draconic might. At least to the extent that it could cause her some trouble.
Eren wasn't someone she could easily get rid of despite the obvious ranking difference between them.
She knew he couldn't sustain his God Spark usage for long with his mortal vessel. Instead of allowing him to wield his God Spark, she decided to rip him to pieces with her overwhelming physical might and weapon comprehension.
One could say that the dragoness hated being seen as a whetstone to sharpen a certain someone's divine abilities. With a powerful flap of her draconic wings, she appeared right in front of Eren in the blink of an eye.