Q. You mentioned (on question 1979) that women should not recite kaddish in the women’s section behind the mechitza. What happens if a woman does recite and you hear her. Do you have to answer Yehei Shmei Rabba? How about answering amen when a woman makes a brocho?
A. Mishna Berura (124: 47) quoting P’ri Megodim rules that one may answer amen after the brocho recited by a woman, however, it is not obligatory. (See reason in Notrei Amen ch. 19 and others).
If there is a man present also reciting kaddish in the minyan in the shul, one would be obliged to answer his kaddish. If the woman is the only one reciting kaddish in the ezras noshim, Horav Shlomo Miller’s Shlit’a opinion is that one should not answer since there is no minyan present in her side of the mechitza and therefore the kaddish should not be said.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a