Just my own opinion, but I think it was a very deliberate move that Lori sent Tylee back inside the home AFTER shots were fired to get Lori's purse.
She made sure Tylee was a witness as completely as possible.
I cannot think why else anyone would do it. Shots were fired, you're fleeing with your kids, either because you're afraid or because you don't want them to see the body. But no, Tylee honey, run back in and grab my purse? Inside, where the body of your stepfather is laid out, where the air still reeks of gunsmoke? Where Alex is not rendering aid, not giving CPR, just mooching about until he's sure there's no hope of revival?
Sending Tylee back in just gave Lori more reasons to follow through on killing her.
Lori didn't mention it, as far as I know, in her police interview, but Tylee does. Her describing 'blocking everything out' while she runs inside for the purse is just devastating. And it's a clear sign of how much she did love and respect her mother. She didn't say 'hell no!' She was a dutiful daughter and ran back into a murder scene, even though there's no reason Lori couldn't have got her own purse.
MOO