There is no doubt that it is forbidden for a woman to dance for men.[1] As for a woman's dancing for women in parties or weddings which are not likely to be frequented by men, the opinions of the grand jurists are as under:
Grand jurists like Ayatollah Bahjat, Ayatollah Fazel Lankarani, Ayatollah Wahid Khurasani, Ayatollah Sistani and Ayatollah Noori: "It is not permissible, as an obligatory precaution."[2]
Ayatollah Tabrizi, Ayatollah Khamenei and Imam Khomeini: "If dancing does not entail sexual excitation or committing a ḥarām act, there is no problem (but it is befitting of a Muslim believer to avoid lahw i.e. diversions and frivolity.)[3]
Ayatollah Saafi, Ayatollah Makarem Shirazi: "It is forbidden for a woman to dance for another woman."[4]
[1] - Other than husband
[2] - Ayatollah Fazel Lankarani, Jami' al-Masail, vol.1, question 1736; Ayatollah Sistani, sistani.org, dancing, No. 3; Ayatollah Noor Hamedani, Istiftaat, vol.2, question 574; Ayatollah Bahjat, Tawzih al-Masail, issue No.1.
[3] - Ayatollah Tabrizi, Istiftaat, question 1042, Ayatollah Khamenei, Answers, question 1168, Office: Imam Khomeini.
[4] - Ayatollah Makarem, Istiftaat, vol.1, question 537; Ayatollah Saafi, Jami' al-Ahkaam, vol.2, question 1580 cited from Porsman Software.