My mom wants to know what our side of the family gave as gifts, ie amounts of monetary gifts, so she feels comfortable knowing what to contribute to their family's events. For instance, if a family gave us $250, maybe because they felt extra close to us, my mom may consider contributing something more than $50 to their daughter's wedding. I agree with my mom. I also don't think it's that big a deal.
However, my wife is adamant that no one know, and repeatedly says, "It's none of her business." That's the only reason I can squeeze out.
What's the proper etiquette here?