Agree 100%, you brought up pretty much everything I was going to say. Going through this horror for the second time and watching her home fall into ruin while being stalked by a monstrous hitman, with her only allies being Umbrella soldiers of all people, becoming infected with the T-virus and getting cured just to find out that a missile is headed for the city to destroy everything... wow! I wouldn't have blamed her if she had just given up at some point.
I wouldn't want to be in Claire's shoes either, but her ordeal seems like a "softened" version of Jill's: She also watches the downfall of the city, but it's not her own, and she learns early on that the person she's looking for is not even there anymore. She also has to get out of a place that's about to blow up, but it's "only" a single building complex, not the entire city. She's protecting someone who is the target of a BOW, but she's not the target herself, and as someone else said, that makes a huge difference. That same character also becomes infected and Claire then has to cook up the antidote, but at no point is she at risk of turning into a monster herself. If anything, Sherry's traumatic experiences could be compared to Jill's, not Claire's. And I dare say Leon had an even easier time because he was a trained cop, and got help from Ada, arguably the most capable player in the field at the time.