Chop a bunch of onions into large strips/rings. In a big skillet over medium heat, swirl a little oil till shiny, then add the onions, liver, and 2-3 strips of bacon. Fry for 15-20 minutes, stirring every 3-4 minutes. Add salt and pepper. Serve with mashed potatoes and sauteed spinach. Let her add ketchup if she wants to (or A-1 or Pick-a-Peppa sauce if she likes that).
If she doesn't like it she doesn't like it. It's a bit of a grownup taste. I didn't start liking it till about 12.