In Harry Potter and the Chamber of Secrets, it is understandable why Hermione has a crush on Gilderoy Lockhart: he was handsome, she was a little girl, so she had a fan-girl crush on him, like normal girls to music/movie stars of her age.
At the end of Chamber of Secrets Harry and Ron realized that all his achievements were fake (after Lockhart told them so). I would assume that by the time when trio visits St. Mungo's for the first time, Hermione would be aware of why Lockhart was dismissed, or realized Lockhart's deceptions.
However, when visiting St. Mungo in 5th book, she was breathless, when she saw Lockhart again.
‘Oh, my goodness,’ said Hermione suddenly, sounding breathless. ‘Professor Lockhart!’
My interpretation back when I've read it for the first time long ago was that Hermione still had a crush on him. Is that really the case, or is it my wrong interpretation of her reaction?