Measure for Measure: Isabella's character analysis

The main character, Isabella, is a very virtuous and chaste young woman who faces a difficult decision when her brother is sentenced to death for fornication (unlawful sex). Isabella does not approve of her brother's actions at all, but she pleads for his life out of loyalty and sisterly devotion. She is a spiritual person who starts off wanting to become a nun, however her decision to enter a convent is never explained. She is …

…acting purely out of religious and moral concerns, she must have some thought for herself as well. She does not want to have sexual relations with Angelo, and she knows that she should not have to do that. However, her brother's life is at stake. Perhaps she is right to protect herself and her principles, especially considering that she believes in an afterlife. But on the other hand, perhaps she is too cold and selfish.