Just called my grandchild a "spawn" and she has been upset all day about it

Her mom is currently participating in a meeting with the rest of the family to discuss this. The child is 8. My mistake was I was talking to my son about my granddaughter's misbehavior and she has super hearing and is currently mad at me for it. I'm not going to apologize I'm just going to tell her that maybe she should not eavesdrop. Oh well.