It is one of our customs to have a henna party for the bride, and she receives presents in the form of money. What is the ruling on accepting this money?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Whatever is given to one of the newlyweds on occasion of the wedding is considered a gift for whomever of them received it; he may accept it and should reciprocate for it. It is a custom that the people who give presents on such occasions do this with the intention of receiving similar presents on similar occasions.

In Minah Al-Jaleel, Al-Baji said:

It is a custom for people in our country to give sheep and other things as presents during wedding parties. Ibn Al-‘Attar said that the person who receives a present on such occasions is required to give back a similar gift in similar occasions.

We would like to point out that a Muslim should give presents to his fellow Muslims, whether on occasions or at other times, with the sole intention of helping them, contributing to the costs of the permissible celebrations generally held on weddings, and bringing happiness to them. One should not do this out of pride, to squander, or for one's reputation. 

Allaah Knows best.