Though she be but little she is fierce.
Act 3 Scene 2 line 335
This characterisation of Hermia goes from her former-friend-now-rival Helena in Act 3 Scene 2. Helena knows pretty well that Hermia isn’t satisfied with her height and deliberately presses the sore point, even when she tries to avoid the fight with her. Helena claims that Hermia was too strong and eager to fight even in school and now complains that Hermia can hurt her if provoked - thus provoking Hermia even more.
Despite they all are influenced by the magic of the Fair Folk, this quarrel shows the sharp contrast between petty Helena and independent Hermia. If Helena resorts to whining and asking the men for protection, Hermia is ready to make decisions for herself. She herself eloped to the wild forest with the man she loves and she is ready to defend herself with words and fists, if needed, when the peaceful ways to reconcile don’t work. From Hermia’s reply we see that she is indeed fierce, having a hair-trigger temper, especially when it comes to the love affairs and love triangles.