First of all, not all Catholic teaching is explicitly stated in scripture. After all, the Church came before the Bible was canonized and before the New Testament was even written. Also, be advised the Church does not require anyone to believe in any apparition. The Church has accepted certain apparitions as true, because there is nothing contained within them that conflicts with the teaching of the Church, and because they could find nothing to suggest that the apparitions were fraudulent in nature. The well known apparitions such as Fatima and Lourdes had some pretty stunning miracles associated with them. Since the Blessed Virgin has no power on her own to perform these miracles, it is only logical to assume that God was involved in them.
As far as scripture is concerned the only thing that comes to me right now is that we are told in the Bible that in the resurrection people will “be as the angels” (Mt 22:30). Since God repeatedly allowed angels to appear in apparitions, I see know reason why a saint could not. I don’t know what you mean by “these” apparitions. There are several apparitions that are under investigation, and some that are out and out frauds. We are prohibited from discussing unapproved apparitions in the forum.
Not to be disrespectful, but I would refrain from the phrase “Mama Mary”. I will give you the benefit of the doubt that you are using a term of endearment, however, it seems a bit disrespectful in print.
