My wife generally lights candles 15 minutes before sunset, in keeping with our community’s practice. I generally cease melacha then, as do she and our two little children. Sometimes, due to work, I can make it home only by sunset, not candle lighting time. May my wife light at the usual time or should she wait for me? I am afraid that my small children, who are used to my not doing melacha after my wife lights, will be confused.
A community’s candle lighting time is not the time that all community members are expected to accept Shabbat but is the first formal action done towards that end. The Behag (cited in the Tur and Shulchan Aruch, Orach Chayim 263:10) posits that a woman accepts Shabbat with this lighting. This is true at least for Ashkenazi women (see Rama, ad loc.), who for this reason recite the beracha only after completing lighting (see Darchei Moshe, OC 263:2). (The ruling for Sephardi women is more complicated – see Yabia Omer, IX, OC 24).
However, lighting candles is not a home’s absolute acceptance of Shabbat. For one thing, the Rama (ibid.) allows a woman to not accept Shabbat by lighting by means of even a mental condition. After all, lighting is innately a preparatory act before Shabbat, not an act of Shabbat, such as davening Maariv or making Kiddush. In fact, men do not accept Shabbat when they light candles (Mishna Berura 263:42).
On the other hand, there are several indications that candle lighting it is not merely a technical preparatory act. First, we must light Shabbat candles even if we are happy with the existing light situation and this mitzva is accompanied by a special beracha. Additionally, not everyone allows a woman to make a condition to light candles without accepting Shabbat. We rule it requires a real need (Magen Avraham 263:20; Mishna Berura 263:44; see Shemirat Shabbat K’hilchata 43:24).
Regarding your question, the Rama states clearly that members of the household other than the woman who lights do not accept Shabbat with that lighting. Most men do not want to accept because they want to daven Mincha in shul, which is usually after candle lighting time (women should daven Mincha before (Mishna Berura 263:43)) and often will drive there. In some households, daughters generally accept Shabbat when their mother lights, which has a certain appropriateness to it. However, it is not halacha and in many households, after lighting candles, there may still be work to do. Therefore, it is not always healthy to expect the whole family to be ready or for the mother to feel the pressure that she must be sure everything is taken care of before she lights.
Do not teach your children that their father must cease work after their mother lights candles. Your assumption that it is confusing is based on your assumption that this is proper. To the contrary, it is confusing to see you being careful not to do melacha while neighbors are driving to shul.
Certainly there are many advantages to a father being home well before Shabbat, but life is not always that obliging. There is some question whether there is a minimum time before sunset to stop doing melacha for tosefet (early acceptance of) Shabbat (see Rosh, Berachot 4:6), and we usually assume a few minutes is enough. Of course, the closer to Shabbat, the more preferable it is to not do melacha. Forgetting the rejected opinion that bein hashemashot begins several minutes before sunset, according to some opinions, the time of sunset is affected a few minutes due to mountains in the area. On practical grounds, one’s watch can be off, he can forget the exact time, or he could lose track of time under the pressure of last minute delays. Therefore, it is prudent although halachically not required to leave at least, say, five minutes before sunset to be finished with all traveling and other melacha.
In short, your wife need not wait for you and should not wait more than a few minutes. Her correct time and yours are not linked.