I'm sorry for your family's loss.

Beware appealing to the prospect of leniency that seems associated with the bereavement fare, however. I attempted to book one on NW some years ago--if they are now as they were then, they're more liberal with changes, but they are also much more expensive than the discounted tickets you already hold. (They were about double the walkup price for DTW-EWR tickets one week out at the time.)

I'd plead for mercy on the change fee without reference to bereavement rates.