Staircase

In the movie, She mentioned how her husband didn't finish the stairs and to be careful. The baby wasn't crawling yet, let alone sitting up. I'm sure they would have the bannister up and working by then along with some safety gates.

Im sure if this were real life they would hv baby proof the house but because its for play play lets just pretend they just ordered the gates from Amazon and they will arrive in 2 days since they are Prime members