The Prophet ﷺ said, "If a woman gives in charity from her house meals without wasting (i.e. being extravagant), she will get the reward for her giving, and her husband will also get the reward for his earning and the storekeeper will also get a similar reward. The acquisition of the reward of none of them will reduce the reward of the others."  

قَالَ النَّبِيُّ ﷺ إِذَا أَنْفَقَتِ الْمَرْأَةُ مِنْ طَعَامِ بَيْتِهَا غَيْرَ مُفْسِدَةٍ كَانَ لَهَا أَجْرُهَا بِمَا أَنْفَقَتْ وَلِزَوْجِهَا بِمَا كَسَبَ وَلِلْخَازِنِ مِثْلُ ذَلِكَ لاَ يَنْقُصُ بَعْضُهُمْ أَجْرَ بَعْضٍ شَيْئًا  

The Prophet ﷺ said, "If a woman gives something (i.e. in charity) from her husband's earnings without his permission, she will get half his reward."  

عَنِ النَّبِيِّ ﷺ قَالَ إِذَا أَنْفَقَتِ الْمَرْأَةُ مِنْ كَسْبِ زَوْجِهَا عَنْ غَيْرِ أَمْرِهِ فَلَهُ نِصْفُ أَجْرِهِ