Hello, I am reading Life after life by Kate Atkinson. Her sister-in-law loved a married man and got pregnant. ‘If only the bounder hadn’t been married,’ Hugh said. ‘He could have made an honest woman of my sister.’ ‘An honest woman?’ Sylvie mused. ‘Is there such a thing?’ I wonder what does the meaning of "an honest woman" in this case. Why does Sylvie ask if there was such a thing? Please help me. Thank you.