Answer:
Yes, in the question there are is a clear example of economic discrimination.
Explanation:
The fact that Sharna does not purchase Earth prodcuts is not economic discrimination because each consumer is free to decide what to purchase.
However, Sharna is not only a consumer, but also a producer, and one that is a monopoly, and using the power of her monopolistic position to refuse to sell to Earthlings, or loan less to Earthlings, not because of legitimate economic justifications or concerns, but because she dislikes Earthling poetry, is a clear example of economic discrimination that would be struck down in an Earthling court.