The Shevet Halevi (Vol.5 132:7) disagrees with this ruling. He references the Halacha (YD 148:1)that even when Bais Din forces a person to give Tzedaka, they may only take his property in his presence, with his knowledge. Surely a woman, even if she is acting on the directive of the Rav, has no more authority than a Bais Din.   

If the Woman is the Breadwinner

The above discussion is in the case that the husband earns the household money, and the wife wishes to donate some of it to Tzedaka. Another issue discussed by the Poskim is when the woman isthe primary breadwinner. Does she then have the right to give whatever money she chooses to Tzedaka?  

The Halacha is that a man is obligated to support his wife financially. In exchange for this support, Chazal decreed that whatever money the woman earns belongs to her husband (However, a woman has the option to waive her right to be supported by her husband, in which case she retains whatever she earns). The question is if the husband does not actually support her, does he nonetheless acquire his wife’s earnings?

This question is addressed by the Maharit (Vol. 2 CM 67). He distinguishes between whether the woman supports her husband from the outset of the marriage, and where the husband initially supports his wife, and only later she becomes the breadwinner. In the former case, the wife definitely retains the money she earns. In the latter case, there is a debate among the Acharonim as to the Maharit’s intention. Some explain that he is unsure who the money belongs to, while others understand him to mean that it belongs to the husband (see Pischei Choshen vol. 9 Ch 10, note 21).

The Chazon Ish (EH 70:6) rules that even if the husband supported his wife only at the very beginning of the marriage, he still retains ownership of all her subsequent income. Since he was providing for her when she earned her first paycheck, he acquired that paycheck. When he uses that money to continue supporting her, he has provided her from money that belongs to him. That entitles him to acquire the next paycheck. This cycle repeats itself, causing the husband to perpetually acquire his wife’s income.

It is noteworthy that there is some debate among the Acharonim in the event that the woman’s parents support the couple. The Shu”t Giva’as Shaul (Siman 33) considers any parental support as discharging the husband’s obligation, enabling him to acquire his wife’s earnings.  

However, the Maharsham (vol. 4, 92) disagrees. He says that support given to the couple by the wife’s parents is intended solely to be for the wife’s benefit, and does not constitute support by the husband. However, money received by the couple as wedding gifts definitely belongs to the husband.

Another consideration is that even if the money does belong to her, there is further disagreement among the Acharonim whether she may keep it outright, or whether it must be invested in a manner that enables the husband to benefit from the profits that accrue (see Igros Moshe EH Vol 1:106 per Gilyon Rabbi Akiva Eiger EH 80:1; cf Bais Meir ad loc who questions this premise). According to this opinion she would not be permitted to donate the money without her husband’s consent.  

In summary, if the wife is the primary breadwinner, there is debate as to the status of the household money, and according to some it depends on exactly what happened at the outset of the marriage.

On a final note, the Shevet Halevi (vol. 2, 118) brings from the Maharshal that although a woman is generally only permitted to make a minor donation to Tzedaka, if she is the breadwinner she can assume that her husband gives her permission to make any donation she wants. Even if technically the money is his, since if he were to protest his wife’s generosity she may discontinue earning money, we assume that he gives her permission to donate as she sees fit.