Aside from the gut punch of Denny almost dying in an otherwise silly episode, the other thing that bothered me about Wilson family plot was Karen complaining about Hen working on Halloween. She's used to this. It's part of the deal when you're married to a firefighter, and taking three kids trick-or-treating isn't all that hard when two of them are as old as Denny and Mara. Complaining about it didn't feel like a Karen thing to do.
I think it would have been much more interesting if Mara was the one who had a hard time with it. Sure, she's been living with first responders for seven months or so, but Halloween might be the first Big Occasion that one of her moms or foster parents has missed. We could have had some great scenes with Denny and Mara (played by two fantastic young actors!) talking about it, or Mara giving Hen a bit of the cold shoulder when she doesn't take the night off.
And it would be neat for Mara to see Hen being amazing at her job for the first time, and then change her mind about Hen missing Halloween with the family.
Anyways the Henren disagreement felt like cooked-up drama, when we could have had something more interesting and realistic about Mara adjusting to her new family.