Is it that bad to laugh at someone's accent?

Apparently there has been a new student in our AP calculus class since the starting of February. Though I don't tell her anything nor comment, within me sometimes I find her acccent funny.

One time I just started laughing (not too loud though) for several seconds but she didn't know it me.
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+1 y
Her accent is kind of strong sometimes. I just find it funny.
Is it that bad to laugh at someone's accent?
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