Am I understanding this story right?

Ok, it goes like this...

The candle gave the abuela a gift where her children will have magical powers, the purpose of which was to help them survive and prosper as a family.

Years later, the abuela was putting enormous pressure on family members to use their powers to be perfect. It was to the point where it was making them stressed and unhappy. The candle started to doubt whether the abuela continued to be worthy of this gift, because making family members unhappy goes against the rationale behind giving them the gift in the first place.

So the candle withheld giving Mirabella any magical powers as a test. If it caused the abuela to look down on her and treat her as a less valued member of the family, then the abuela would be considered no longer worthy of being blessed with this gift, and all powers would be taken from the family. Due to her harsh treatment of Mirabella, it appears the abuela failed this test.

Only if without their powers, the abuela sees the error of her ways, and the family is able to reconcile with each other and work together, would they come back into the good graces of the candle and have their powers returned. They demonstrate this by rebuilding their home, and their powers are returned.