In fact, the ceremony is just a formality, not quantity, not money. The key is that more people are happy and lively, and we also include happy money (120-400) in the invitation, which shows that you are just a gift. Thirdly, we apologize for the delay of the guests attending the celebration. Customs vary from place to place, but the same is for everyone's happiness and celebration. If it is for the purpose of how much gift money is collected by borrowing business, it will be bad, and the festive things will become stale. Besides, if you return the gift, you will return it to others in the future, so don't care too much about the amount of the gift, and the gift is light and heavy!
Because it's your brother, it depends on how much you want your mother-in-law to take.