Are women obligated to listen to Parashat Zachor, and what is the halacha with someone who cannot come to the bet knesset to listen to Parshat Zachor?
According to the overwhelming majority of poskim, women are not obligated to remember Amalek because remembering Amalek is associated with the fact that we Jews need to destroy and annihilate them. Since women are not commanded to fight, they are not part of remembering Amalek's unwarranted attack (chinuch, 603).
Some poskim say that women are also part of the war against Amalak since they can aid and support the fighters even if they are not in the battle itself. Therefore, they also have a part in remembering Amalek. Although the sages assigned a set time to remind ourselves of what Amalek had done to the Jews, (the Shabbat prior to Purim), by biblical law there is no set time. Remembering Amalak is not a time bound mitzva where women are exempt.
Today, many communities have a custom after services to read Parshat Zachor from the Sefer Torah for women. That way the women can go to the bet knesset to listen to Parshat Zachor while their husbands go home to take care of the children.
If a person is not able to come to the bet knesset, they should fulfill the obligation of reading Parshat Zachor when the time comes to read Parshat Ki Tetzeh. Rav Ovadiah says that a person who cannot come to the bet knesset should read Parashat Zachor at home from a printed Chumash.
Regarding the pronunciation used when reading the parasha, Rav Ovadiah says that when it comes to Parshat Zachor and Parshat Parah, many hold that it is de'oraita (i.e. a law directly from the Torah) as we can see in the Shulchan Aruch (Siman 146 Se'if 2), each person should go to the bet knesset that follows their father's custom. Therefore, if Sefardim are learning in an Ashkenazi yeshiva, they should make their own minyan that week and read the parasha in a Sephardi pronunciation.