What is the ruling on a mother laughing near a window in such a way that a strange man can hear her?

If a woman is in her home, she is not obligated to investigate whether there is a non-mahram man near her house or not. This is because requiring her to do so would involve a kind of hardship that is removed by the Sharia, based on Allah’s saying: "And He has not placed upon you in the religion any difficulty."