There are two areas designated for the women. Both are located at the back of the mosque near the main hotel areas. The respective courtyard area around these locations are also designated for the women.
The Saudi guards will chase you away – even making you break your prayer – if you try to pray elsewhere when the official group prayer is occurring with the imam.
If your hotel is near the Prophet’s grave (the green dome), it can take anywhere from fifteen minutes or more to reach the women’s area when walking. Take care to plan out how much time you need to reach the prayer area so that you can catch the group prayers with the imam inshaAllah.