This is correct. Sheila appeals to the case of making film adaptations of written works, which she believes is analogous to making colorized versions of black and white films.

Sheila's example of making film adaptations of written works isn't a counterexample to anything. If anything, it is used to suggest a more general principle — new works of art should be judged separately from the originals — which Sarah then argues applies to the original case of colorized versus black-and-white films. So if this idea is taken as a principle, there are no counterexamples to it in this argument — though notice that the idea is actually framed less as a general principle as simply an important point of similarity between two analogous cases. We don't know if Sheila necessarily believes this idea is a principle that applies in all cases beyond these two.

Though Sheila does say "no one" argues that making a film adaptation of a written work threatens the value of the original, she agrees with that argument not because of the number of people who believe it, but because of the logic behind it: the film adaptation, as a new work of art, should be judged separately from the original. And Sheila doesn't say anything at all about popular opinion regarding colorized versus black-and-white films.

Sheila does not say anything about facts versus value judgments.

The structure this answer choice describes would look more like Sheila offering a general rule to begin with, and then examining the details of the process of colorizing black and white films to see if the rule applied to that case. She doesn't do this. Her argument is based on appealing to an analogous case.