Abuela doesn't even shit the bed. Think about it.
Her family is saved by a miracle after her husband is killed. From her perspective this may be what? The soul of her husband? The spirit of the land taking pity? God? Then she raises her kids and they turn out to be complete fucksticks after they're blessed again with magic powers.
Bruno uses premonition to tease and humiliate people. Sadsack just cries and makes thunderstorms and is useless if not dangerous. You have one good daughter, thank God who granted you this power, who heals the sick with food. Unfortunately, she isn't very ambitious and doesn't stand out, meaning your two problem children become the most notable.
Then they have kids. One of them gets super strength and she's helpful. Your husband died for this, you're glad she's responsible. But then one of them gets super hearing and just treats everything like her personal soap opera. She can hear when a man beats his wife, but does she help? Tell anyone? No. She even ignores Bruno hiding in the walls. If it's not fun and juicy she doesn't give a fuck, and if it is, she tells everyone. You get a girl whose power is that she's pretty, and she clearly has no appreciation for it, taking it for granted. And then the shape-shifter, who thinks he's funny. Lord.
But Mirabelle. Most of these kids are clearly unworthy, but the house won't even touch Mirabelle. Why? What does it know? Does it sense something wrong with her? How the fuck could Abuela know the house is an asshole setting her up to fail with a shitty little test? There's no reason to guess that. It must have MEANING.
But in the end, it turns out the house had the skittish personality of all and was just fucking with Abuela for taking it so seriously and thinking her husband's death gave gravity to all of this.