On accident?

The kids are learning the phrase, "On purpose" and "An Accident". As in, "Did you hit your sister in the face on purpose?" Or "Don't be too upset Elizabeth, it was an accident when Parker jumped on your legs."

So today, Miranda is reading In the Night Kitchen and she yells out "QUIET DOWN THERE!" Which for some reason, deeply offends Elizabeth who screams "NO NANA!" Miranda then says, "Biza said NO NANA," while starting to cry. So I tell Elizabeth, "Miranda is just reading the book and she can say Quiet down there and it makes her feel bad when you yell at her."

Then Elizabeth says, "I said No at her on accident."

Parker, who had been quiet this whole time smiled and said, "Not Ah"