A; All-Praise is due to Allah,
The general principle is that women are equal to men in all religious rulings, because of the hadeeth "Women are the twin halves of men" (Reported by Imaam Ahmad and classified as saheeh in Saheeh al-Jaami’ 1983), except when there is evidence (daleel) of a specific ruling which applies only to women. One of the cases in which the scholars mention specific rules for women is prayer, where there are differences as follows:
Women do not have to give adhaan or iqaamah, because adhaan requires raising the voice, which women are not permitted to do. Ibn Qudaamah, may Allaah have mercy on him, said: "We know of no difference between the scholars (on this point)." (Al-Mughni ma’a al-Sharh al-Kabeer, 1/438). All of the woman’s body is ‘awrah and must be covered during prayer, except for her face, because the Prophet (peace and blessings of Allaah be upon him) said: "No prayer will be accepted from an adult woman unless she wears a khimaar (head-cover). (Reported by the five Muhadditheen) There is some dispute as to whether her heels and feet should be covered. The author of al-Mughni (2/328) said: "As for the rest of the free woman’s body, it must be covered during prayer. If any part becomes uncovered, it renders her prayer invalid, except if only a little bit is uncovered. Maalik, al-Oozaa’i and al-Shaafi’i said the same. The woman should keep her limbs close to her body during rukoo’ and sujood, and not spread them out, because this is more modest and covering. (Al-Mughni 2/258). Al-Nawawi said: "Al-Shaafi’i said, in al-Mukhtasar: there is no difference between men and women in prayer, except that women should keep the parts of their bodies close to one another, and they should make their stomachs touch their thighs during sujood. This is more covering and preferable, in rukoo’ and the rest of the prayer too." (See al-Majmoo’ 3/429). It is preferable for women to pray in congregation, led by one of their number, because the Prophet (peace and blessings of Allaah be upon him) told Umm Waraqah to lead the women of her household in prayer. There is some difference among scholars on this matter. (See al-Mughni, 2/202 and al-Majmoo’ al-Nawawi, 4/84-85). The woman leading the prayer should read aloud as long as no non-mahram man can hear her. It is permissible for women to go out and pray in the mosque with men, although their prayer at home is better for them, because the Prophet (peace and blessings of Allaah be upon him) said: "Do not prevent the women from going out to the mosques, even though their homes are better for them." (For more details on this matter, see Question#973). Imaam al-Nawawi, may Allaah have mercy on him, said (al-Majmoo’ 3/455): "Women differ from men in congregational prayer in a number of ways:
(1) Congregational prayer is not required of them in the same way as it is of men.
(2) The imam of a group of women stands in the middle of the (first) row.
(3) (If one woman and one man are praying), she should stand behind him, not next to him.
(4) If women are praying in rows behind men, the back rows are better for them than the front rows.
What we can learn from the above is that women and men are forbidden to mix.
It is permissible for women to pray in congregation among themselves. Their leader should stand in the middle of the row according to the narration regarding Aa’ishah (may Allaah be pleased with her) which indicates that she used to lead women in prayer and would stand with them in the middle of the row. This has been narrated by ‘Abdur Razzaq in Al-Musannaf 3/141 and Daraqutni 1/404, and is authentic due to evidences for it.
Similarly Umm Al-Hasan narrated that she saw Umm Salmah (may Allaah be pleased with her) leading women in prayer while she stood in the middle of their row. This has been narrated by Ibn Abee Shaybah 2/88 and is also authentic due to other supporting evidences.
Ibn Qudamah has quoted the difference of opinion on whether congregation for women is recommended, and then says about their leader: “The one who leads them should stand in the middle of the row. We do not know of a difference of opinion on this among those who support that one women may lead others in congregation. Since it is recommended for the women to be covered, ….. standing in the middle of the row makes it a better covering for her from the sides.”(Al-Mughni, 2/202)
The author of Al-Muhadhdhab (4/295) says: “It is sunnah that the leader of women in congregation stand in the middle of them as narrated about ‘Aa’ishah and Umm Salmah that they lead women and stood in the middle of their row.”
For further details refer to Jaami‘ Ahkaam Al-Nisaa’ by Al-‘Adawi (1/351).
And Allaah knows what is most correct and best.
See Islam Q&A Fatwa's: 1106 & 258.