Just thinking out loud here: They are two scenarios with the kids in car. They were in the car when she hit dad's car. Or they were in the house and she would have had to have taken them back out to the car after dad left. I'm betting dad knows when he left whether the kids were in the car or the house.
But I don't see how someone can go from alert enough and freaking out over an affair and bashing a car to black out drunk in minutes. You can't go from that to walking in the house leaving crying kids and blackout drunk in two minutes can you? No experience here myself. So was she black out drunk when she found out about affair? Or got drunk afterwards? If before that's odd. She just happened to be black out drunk when she found out her dh was having an affair? But even if she was drunk when she found out she still had to have gotten the kids out in the car after finding out at some point. Harder to do that while so drunk you are about to black out even more so to buckle them in seats.
Super drunk first: is super drunk when she finds out about affair, loads kids into car, slams dh's car with her and the kids in car, throws brick, he leaves knowing she's super drunk and then she walks inside forgetting kids. Cognizant enough to recognize an affair, flip out over it etc minutes before but not enough to remember that she'd just put kids in the car and needs to get them out?
Sober: finds out about affair, throws brick and slams car, comes inside and gets super drunk, takes kids at some point to car out of revenge, comes inside and sleeps till noon the next day.
Sober: finds out about affair, loads kids in car, then throws brick, slams car into other car, comes inside ignoring kids after dad leaves, gets super drunk, blacks out till noon next day.
I'm guessing the police must have some info at this point about why they are clearly holding her in some related to the kid's deaths. Just like EG was held but we know the real reason. If she was drunk to begin with she'd not likely load the kids up and drive somewhere to shop, then return and forget them would she? That sober and trying to drive?
Was she sober when she flipped out on dh? He leaves and no kids are in the car then? Does she decide she can pretend she went shopping and forgot them or does she ever leave the house with them just for an alibi?
If she was falling down drunk when dh left and he knew kids were in the car then he's certainly in some way responsible for leaving an incredibly drunk woman with a toddler and newborn in a car. But I'm betting this is in some way related to where the kids were when he left and what state he left her in.