My wife would like to know if she may light Chanukah candles in addition to my lightning. You see, we are both in our 40s and got married late, and she has been accustomed to light candles every Chanukah when she lived on her own prior to our marriage. She even bought a special menorah for this purpose which is very sentimental to her. So she would really like to continue with her custom of lighting the candles even if I also light them at home. Is this permitted to be done?
If you are Sephardi, then she may not light Chanukah candles in addition to your lighting. If you are Ashkenazi, then this matter is debated in the Poskim, and it is therefore best for her not to light candles, as is the accepted custom even amongst Ashkenazim for a wife not to light candles on her own, in addition to her husband. Nonetheless, if she chooses to light candles in addition to you she has upon whom to rely, although I would recommend doing so without a blessing and for her to rather fulfill her obligation of the blessing with your blessing and to light right after you light.
Explanation: In a family unit, the obligation to light Chanukah candles falls upon the head of each household. The additional household members who live and are supported by the head of the house are not obligated to light Chanukah candles on their own, and rather fulfill their obligation with the candles of the head of the household. This is from the letter of the law, however regarding whether additional household members may choose to light their own candles as a form of Mihadrin is debated amongst the Poskim, and Ashkenazi and Sephardic custom, and practically according to Sephardic custom they may not do so. Thus, if you are Sephardi it is clear that your wife may not light in addition to your lighting and it is a question of a blessing in vain. However, according to Ashkenazi custom, additional male household members are accustomed to light their own candles although female household members are not accustomed to do so. Thus, the wife is not accustomed to light her own candles even in Ashkenazi homes. However, the question is raised as to the reason why, and the Poskim offer different answers for this question. According to some of these answers it is implied that a wife is not allowed to light candles in addition to her husband either due to the sages not establishing a law of Mehadrin for a wife whose husband is lighting or because a man and his wife are considered like one body and hence when he lights the candles it is literally as if she has lit them as well. Despite this, many Achronim explicitly rule or imply that also the wife may light candles in addition to her husband and may even do so with a blessing. [However, she must have in mind to not be Yotzei with her husband’s lighting in order to be allowed to light her own candles with a blessing.] Hence, practically we concluded that both due to the debate and due to the accepted custom, a wife should not light separately from her husband even according to Ashkenazi custom. Nonetheless, if she chooses to do so she has upon whom to rely, even if she says a blessing, and certainly if she is Yotzei the blessing with her husband.
Sources: See regarding the Ashkenazi versus Sephardic debate if additional household members may light: Michaber 671:2; Rambam 4:1-3; Tur 571:2; Tosafus Shabbos 21b; Rama 671:2; Rif brought in Biur Hagr”a and Biur Halacha 671:2 “Veyesih Omrim”; See regarding the custom for wives not to light candles in addition to their husband even by Ashkenazim: Rashal 85; Kneses Hagedola 671; Elya Raba 671:3; Olas Shmuel 105; Pischeiy Teshuvah; M”B 671:9 and 675:9; Kaf Hachaim 671:16; 675:21; Sefer Haminhagim p. 157 [English]; Minhag Beis Harav, brought in Toras Menachem 5750 2:51; Likkutei Sichos 30:312 “Practically, we do not find that women would light candles on their own”; Toras Menachem 4:233; See Shulchan Menachem 3:274; Minhag Yisrael Torah 671:1 See regarding the letter of the law allowance for a wife to light candles in addition to her husband [even with blessing]: Implication of 2nd opinion in Terumos Hadeshen 101, brought in Taz 677:1, and so rules Taz ibid; Olas Shmuel 105 [even with blessing]; Pischeiy Teshuvah; M”B 675:9 in name of Olas Shmuel even with blessing; See Kaf Hachaim 675:21; Machatzis Hashekel 677:8 in name of Shiltei Giborim [brought in Sefer Haminhagim p. 157 footnote 623] “The Mehadrin have every family member light candles, whether men or women”; Rambam Chanukah 4 “Whether for men or for women”; Kaf Hachaim 671:16; Other opinions that no need light, and certainly not with blessing: Rashal brought in Taz 677:1; Possible understanding of 1st opinion in Terumos Hadeshen 101 who brings a dispute in this matter and concludes that it is considered Mehadrin for the husband/wife to also light. See P”M 677 M”Z 1 for the sides to this debate.