This line, "Woman, frailty is thy name" is of one of the scenes in the play "Hamlet" by Shakespeare, said by the character, Hamlet, in Act 1, Scene 2. Here, Hamlet is voicing his complaint about Gertrude's quick remarriage to his uncle Claudius, the same as Hamlet's father, King Hamlet had given up life.
Here, Hamlet struggles to handle his own emotional state as reflecting his unhappy feelings to the same extent that he resents his mother for yielding to hers without thinking much about the consequences. He is aggrieved by her activities, being aware that he had been warmly welcomed into her family, which underline her unfaithfulness.
On the other hand, it's critical to understand that it's only Hamlet who is going through mental struggle and emotional issues around that woman and he is the one who says that. Whether taking into consideration the peculiarities of the female characters in Shakespeare's plays or the only aspect of his characters' strengths and weaknesses, complexity of Shakespearean women is always impressive and exciting for most modern readers.
Ps taken by me
Eventually, the test of blood illustrates more the protagonist's suspicion toward his himself, his friends, and human nature than the actual infidelity of women.