ISNA did not give details on what the protests were about.
"Roya Toloui was sentenced to five years' imprisonment on the charge of attending the mentioned gatherings and one year's imprisonment on the charge of propaganda activity against the system," Sotoudeh told ISNA.
It was not clear whether Toloui was in the court when the sentence was announced or whether she was tried in absentia.
Last month, a court in Tehran handed down partly suspended prison sentences of up to four years against two female activists who attended a banned rally in the capital to demand greater women's rights, according to Iranian media.
About 100 women protested in Tehran in June against unequal inheritance laws, the difficulties women in Iran face getting a divorce, and the fact their court testimony is worth half that of men.
According to Human Rights Watch, six women have been convicted after taking part in that protest.
The group urged Iran's judiciary last month to overturn the convictions and end its persecution of human rights defenders.
Iran says it does not discriminate against women and says its rules are based on the Sharia.