(Strip Number 4377, Original Publication Date, 5 October 1983)
Panel 1: We start things off with Lizzie telling Elly that she's hungry; Elly, who's drinking her coffee and reading the paper, tells her that dinner's in the oven.
Panel 2: Lizzie explains that she's hungry NOW; Elly tells her that dinner will be in fifteen minutes.
Panel 3: Lizzie's telling her that her tummy can't tell time is somewhat oddly articulate but does manage to get the point across to at least the readers. Elly...not so much.
Summary: Given that Elly tends to forget that children perceive time as dragging along painfully, she probably thinks that Lizzie wants to take even more time away from her poor mother than she can spare or some such nonsense. The odd thing is that I've seen hints that her children have picked up on this belief of hers.