All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
There is no doubt that it is better for a woman to pray at her home than in the mosque as we clarified in Fatwa 92531. This is because by praying at home she will be more concealed and far from crowding with men especially during Hajj when it becomes very crowded and men and women are nearly mixed everywhere.
However, this does not mean that a woman is prohibited from praying at the mosque. Therefore, it is permissible for you to pray at the mosque and stay therein all day long. You are also permitted to sleep in the mosque if you know that men cannot see you, like if you sleep in an area that is allocated for women to pray and men do not enter it or see it. According to our view which is the preponderant opinion of the scholars it is permissible to sleep in the mosque.
Finally, we advise you not to sleep in the mosque because of the crowdedness as we advise you to perform the prayer at your place of residence as this is more rewarding for you and you will be far from men looking at you.
Allaah Knows best.