One notable instance occurs during the Chunin Exams when Naruto faces Gaara, the host of the one-tailed sand beast. Naruto taps into the Nine-Tails' chakra to defeat Gaara but later loses control, transforming into the Nine-Tailed Fox. Hinata witnesses this transformation and is shocked by Naruto's immense power.
Another instance is during the Pain invasion arc, when Naruto's rage over Jiraiya's death triggers the Nine-Tails' influence. Hinata attempts to calm Naruto down and remind him of his true self but ultimately fails.
Despite witnessing these instances, Hinata remains steadfast in her support for Naruto and believes in his ability to control the Nine-Tails' power. Her unwavering faith in Naruto becomes a source of strength for him as he learns to harness the Nine-Tails' chakra without losing control.