Question 42: It is the custom of people to put two stones on the graves of the deceased men, one at one end of the grave and one at the other end of the grave. As for the graves of women, they put three stones; one at one end of the grave, one in the middle and a third at the other end of the grave in order to mark it. They write her name, her father’s name, the date of her death and some Aayahs of the Qur’aan on a stone board which is put on the grave. Is this permissible or not?
Answer: Firstly, We do not know any proof on the permissibility of differentiating between the grave of a woman and the grave of a man with a stone or suchlike and the basic ruling is that there is no need to distinguish between the two… read more here.