What is the ruling on a woman visiting graves and placing water and seeds on the grave, and is this considered mutilation of the deceased?

The ruling on women visiting graves has been previously answered. As for placing water and grains on the grave during a visit, this is contrary to the Sunnah. The statement that water cools the deceased is incorrect; rather, what cools the deceased is his deeds and the supplication of his righteous child for him. Indeed, Ibn Umar (may Allah be pleased with both of them) said upon seeing a tent over a grave: "Remove it, O boy, for only his deeds shade him." Placing water and grains on the grave is not considered a desecration of it.