If a shul is mekabel Shabbos with “Mizmor Shir” at exactly Plag Hamincha, or a few moments thereafter (which is certainly permissible), when should the wife, whose husband davens in that shul, light her Shabbos candles? On the one hand, she cannot light earlier than Plag, but on the other hand, once the husband’s shul took early Shabbos, according to many opinions the wife is also forced to accept Shabbos (although Rav Moshe zatzal has a certain chiddush in regard to this, but outside of Rav Moshe’s opinion, this is the halacha). So when should she light?
Many follow Reb Moshe’s psak.
Teshuvas Eretz Tzvi 113, Teshvas Igros Moshe !:38, Shevet Halevy 7:35, Beer Moshe 2:19, Mari Shteif 42.