A change in circumstances does the trick.

Beth was sitting in the bathroom requesting assistance. We told her that she was too old for that kind of assistance and that she needed to do it herself. She spent the next twenty minutes not doing it herself, asking repeatedly for the assistance that would never come.

“MOM, ARE YOU IGNORING ME?”

Mommy answers with more silence.

“MOM, YOU CAN’T IGNORE ME!”

Mommy answers with more silence.

Two minutes later…
… the door bell rings.

“Can Beth come out and play?”
“I don’t know, Beth is kind of busy right now.”

FLUSH

“MOM, I’M ALMOST DONE!”