Congratulations on the saving of the family quilt. It's a lovely memorial item.
People who do not sew cannot appreciate hand quilting. For a simple reason. When you can purchase a 'quilt' from Walmart for $29.99 and for all intent and purpose it looks like the same thing - it's hard for a non quilter to understand the unique love we have for quilts which are made by us or even understand the whys for the amount of time spent creating something like this.
Ducky, what I would hope I'd do. Keep it quite, no need to further bring attention to your son about it. Whenever possible I'd place the quilt in a prominent place to be shown proudly for ANYONE who entered my home. It's a move to keep the verbal peace but expressing dissatisfaction of an event you found disturbing and if something from the other side should say something about your placement; it's one that cannot be said you made a big deal out of nothing by allowing you to be equally as ignorant of 'WHY' you placed the quilt so prominently displayed, you remember your Aunt and the love you had for her!