User blog comment:B214/Volume 17 spoilers./@comment-16281343-20140220010926/@comment-16281343-20140220012143

They would be ecstatic to know that their daughter is Archangel Michael's Ace and is a reincarnated Angel.

Her parents know the existence of other supernatural beings unlike Issei's parents. They own a Holy Sword which they probably use in exterminating Devils in the past.