Panel 1: We start off looking at Lizzie in her car seat sleeping despite being in noisy cross-town traffic.
Panel 2: We next see Elly, having slammed the door, carrying a sleeping Lizzie and the groceries up to her bedroom; to point out how martyred Elly is, we see unsound effects that say Huff-puff-wheeze.
Panel 3: Mike comes in and yells "MOM, CAN I HAVE A BANANA??" in a voice loud enough to wake the dead; Elly goes "Shh." to remind him that he might wake Lizzie up.
Panel 4: She tiptoes across the floor so as to not disturb her child; since Lynn thinks that people might think she's playing statue, we see the words tip-toe, tip-toe at the bottom of the panel. Meanwhile, Mike is wondering why she's walking like she's a character from Thunderbirds or Captain Scarlet and the Mysterons.
Panel 5: Elly gently clicks the door shut behind her.....
Panel 6: ....only to make the Triangle of Horror when Lizzie starts crying.
Summary: The point that Lynn was probably trying to make was that despite every attempt that a busy mother with no help and no time to herself made to keep her child quiet, she started crying and spoiled things. What, of course, a normal person would take away from this is that we really can't predict when a child is going to wake up or what will do it; all we can do is remember that despite what Lynn believes, they aren't deliberately out to make our lives miserable.