Man Panel conquers the How Important is the Ring Question

Dear MAN PANEL

I am planning to propose to my girlfriend on Christmas Day. My mom wants me to use a diamond ring that has been in our family for generations. My girlfriend hates the ring and will most likely say NO to the proposal if I use it. My mother is extreme and insists I use the ring. If I don't, I could lose out on my $900,000 inheritance when she passes. I have a crazy family and don't know what to do. Can you help me