>>109968119Maybe you've just been misinterpreting her character. Her loyalty to Gabriel has always far outweighed whatever sympathy she feels for Adrien, especially when it comes to Hawkmoth related scheming.
Gabriel promised Lila that she'd be allowed access to Adrien as his 'muse' in exchange for her continued service to him, so of course, Natalie isn't going to defy him. Just like she didn't call out Gabriel for Akumatizing himself, despite how obviously dangerous that was to Adrien.