Panel 2: Oh, I get it. When we finally see Deanna featured in a Sunday strip with her kids, it's because there's a real problem to deal with. And if you want to explore a problem in depth, it has to be Deanna; she can't hand the kids off to anyone!
Panel 3: Good job on the toys. But what the heck is Merrie doing? Don't tell me she's going to push the playpen over! That's just the kind of scary thing siblings do to each other, but it seems awfully dark for FOOB.
The horrible, endless fighting between Mike an' Lizzie that Elly remembers never had any psychological overtones, nor was physically dangerous. The worst either of them got hurt was when Mike slammed Lizzie's finger in a door, requiring a hospital visit, and that was an accident. The only really scummy thing either of them did was Liz, when Mike was on the phone with Deanna, pretending to be his "other" girlfriend, loud enough for Deanna to hear, but that was when she was in her late teens. (It was also before Eric was established as a cheater, interestingly enough.)
Panel 4: No, she's not pushing any more. So she's either yelling at him to shut up, in which case the joke is that she's just making it worse, or she's trying to out-yell him, in which case the joke is...I dunno, some inverted cliche.
Panel 5: Okay, so Deanna gives in to him, and either gives his a pacifier or lets him suck his thumb. Great. Well, I won't judge her; she has no help with these kids. Has to do what she has to do.
Panel 6: Oh, now Merrie wants attention. Or she's trying to start the duet again.
Panel 7: Oh, she wants in the playpen! A case of always wanting what the other kid has? Or more of her refusal to give up "baby" status because she was in that role first.
Panel 8: That was the other option I should have mentioned: the easy out of "Kids sure are strange." Really: What's so hard to understand? Both kids are quiet, because they're comfortable where they are. Dunno what she's so pissed off about. And that squiggle, which I assume is supposed to be reflected light, looks more like the pancake syrup spilled and congealed there.