Aisha(RA) reported: The Messenger of Allah, peace and blessings be upon him, said:
When a woman spends in charity from her house’s meal without wasting it, then she will have a reward from what she spent. Her husband will have a reward from what he earned and the storekeeper will have a similar reward. Their rewards will not decrease each other in anything.
Source: Sahih Bukhari 1359,