Amount to give to charity in honor of marriage

[Anonymous]

I have a work colleague who is getting married. I am friendly with the colleague and their partner outside of work. It is a second marriage for both of them and they are in their early 50s. My partner and I are going to the wedding. They have asked for donations to a charity instead of gifts. If they asked for a gift, I know how much we would give. Do I make the same size donation, or do I donate less?

[Anonymous]

Same size.