In the play "Romeo and Juliet" by William Shakespeare, it is interesting to note that ,for Juliet, it is never an option to just go ahead and marry Paris without saying anything. This option would have bought her some time while they all thought about waht to do to solve the problem. That alternative, to accept the County Paris, is obviously a fate worse than death for Juliet. Romeo would not have been too pleased either. Her actual response is very illuminating for us as readers. Elsewhere in the play she is described as "hot" and "sweet." Here, she is showing her impulsive and passionate side. The irony about the suicide idea is that she fulfils the foreshadowing of death throughout the play by dying anyway.
In Act IV, Scene 1, Juliet is talking to Friar Lawrence about what she can do. She does not want to marry Paris, but her parents are insisting on it very strongly.
At that point, she thinks that her best option or only option is to just go ahead and kill herself. She tells Friar Lawrence that she would rather die (she tells him all sorts of ways she'd rather die) than marry Paris. For example:
O, bid me leap, rather than marry Paris,
From off the battlements of yonder tower
It is at this point that Friar Lawrence comes up with his idea about having her take that potion.
She thinks that killing herself is her solution but when she went to friar lawrence and he told her about the plan "poison" ...... etc..