The Halachic authorities debate the question as to whether a woman may pray Minha on Friday afternoon after she lit the Shabbat candles. Ideally, a woman who normally recites Minha every day should recite Minha on Friday afternoon before she lights the Shabbat candles. Lighting the Shabbat candles constitutes the formal acceptance of Shabbat, and so Minha, which is a weekday prayer, should be recited prior to candle lighting. The case under discussion is where a woman who normally prays Minha every day forgot to recite the prayer before lighting the Shabbat candles on Friday afternoon. Assuming the sun has not set, and thus the time for Minha has not passed, may she still recite Minha, or is it too late for her to pray Minha, since she has already accepted the onset of Shabbat?
The Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909) rules that a woman may not pray Minha once she lit the Shabbat candles and accepted Shabbat. This is also the position of the Mishna Berura (commentary by Rav Yisrael Meir Kagan of Radin, 1839-1933), in Siman 263 (Se’if Katan 43). Hacham Ovadia Yosef, however, disagrees, and allows a woman to recite Minha in this case. His primary argument relates to a distinction between an individual’s formal acceptance of Shabbat, and that of a congregation. When a congregation accepts Shabbat in the synagogue, such as by declaring "Bo’i Kalla" in the Kabbalat Shabbat service, this constitutes a definitive acceptance with respect to all Halachot. An individual’s acceptance of Shabbat, however, as in the case of a woman lighting the Shabbat candles, is not absolute. Under certain circumstances, such as when a woman forgot to recite Minha before candle lighting, she may consider Shabbat as having not yet begun, and may thus recite Minha.
Additionally, Hacham Ovadia notes, the weekday Amida recited at Minha on Friday afternoon is not necessarily at odds with the observance of Shabbat. Fundamentally, the weekday Amida may be recited even on Shabbat. The Sages formulated a different, briefer Amida prayer for Shabbat in order not to overburden us with a lengthy prayer service on Shabbat, but essentially, the weekday Amida is appropriate for Shabbat, as well. Therefore, in the case of a woman who forgot to recite Minha before candle lighting, she still has the opportunity to recite Minha after candle lighting, even though she has already accepted Shabbat.
Summary: A woman who generally recites Minha should recite the prayer on Friday afternoon before candle lighting. Nevertheless, if she forgot to pray Minha before candle lighting, she may recite it afterward (assuming, of course, that she remembers before sunset).