بسم الله الرحمن الرحيم
(Fatwa: 1049/1049/M=11/1436)
A jamah in which both the imam and muqtadis are only women is makrooh tahrimi whether it is Eid salah or five times salah. Jama’ah is a precondition for the validity of Eid salahs, it is not lawful to offer Eid salahs at home alone. So Eid salah cannot be offered alone. Moreover, the salah of Jumuah and Eidain are not wajib on women. Hence this practice of the women in your city who go to offer Eid salah and offer salah behind lady imam is not correct.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband