Praise be to Allah.
This question deals with two matters.
1 – the preference for women to pray in their homes.
Shaykh Ibn ‘Uthaymeen said: the Sunnah indicates that it is better for a woman to pray at home, no matter where she is, whether she is in Makkah or elsewhere. Hence the Prophet (peace and blessings of Allaah be upon him) said: “Do not prevent the female slaves of Allaah from coming to the mosques of Allaah, but their houses are better for them.”
He said that when he was in Madeenah, even though prayer in the Prophet’s Mosque brings more reward, because a woman’s prayer in her own house is more covering for her and farther removed from temptation (fitnah), so if she is in her house then this is preferable and is better.
See Fataawa al-Jaami’ah li’l-Mar’ah al-Muslimah, vol. 1, p. 207. See also Question # 3457.
The multiplied reward for praying in congregation applies only to men. The Prophet (peace and blessings of Allaah be upon him) said to a woman, “I know that you like to pray with me… but your prayer in your house is better for you than your praying in the mosque of your people…” This hadeeth was narrated by Ahmad (Musnad, Baaqi al-Ansaar, 25842; classed as hasan by al-Albaani in Saheeh al-Targheeb wa’l-Tarheeb, no. 337)
2 – Evidence that when a woman leads other women in prayer, she should stand in the middle of the row.
Ibn Qudaamah said: it is Sunnah, when a woman to lead other women in prayer, for her to stand in the middle of the row in all cases, because they are ‘awrah. Al-Mughni, vol. 1, p. 347
Al-Nawawi said: The Sunnah is for a woman who is leading other women in prayer to stand in the middle of the row, because of the reports which state that ‘Aa’ishah and Umm Salamah led other women and they stood in the midst of them. Al-Majmoo’ Sharh al-Muhadhdab, vol. 4, p. 192
If women pray in congregation, then the one who is leading them should stand in the middle of the row, because that is more concealing, and a woman is required to cover as much as possible. It is known that if a woman stands in the midst of other women it is more concealing than if she were to stand in front of them. The evidence for that is the reports which were narrated from ‘Aa’ishah and Umm Salamah (may Allaah be pleased with them), “When a woman leads other women in prayer, she should stand in the middle of them.” This was the action of the Sahaabi women, and the more correct view is that this action of the Sahaabi women is to be taken as proof because there is no text narrated to the contrary. If a woman is leading one other woman in prayer, she should stand as a man stands with one other man.
See al-Sharh al-Mumti’ by Ibn ‘Uthaymeen, vol. 4, p. 387.