She has a right to.

All young girls are ignorant.

If they begin with a dreadful but innocent mistake does the safety of society require of them the horror of lifelong degradation?
Then the safety of such a society is not worth the sacrifice.

That is my opinion." "That settles a long-vexed problem," he said, laughing at her earnestness.
But she looked at him, unsmiling, while he spoke, hands clasped in her lap, the fingers twisting and tightening till the rose-tinted nails whitened.
* * * * * Men have only a vague idea of women's ignorance; how naturally they are inclined to respond to a man; how the dominating egotism of a man and his confident professions and his demands confuse them; how deeply his appeals for his own happiness stir them to pity....

They have heard of love--and they do not know.