The two prior posts say it exactly right. Remember the case of Nestorius. He was a bishop and had the full backing of the Emperor. He was even the "legal" holder of the office of the bishop at the time. But when he declared a single heresy at the Christmas Mass (that Mary should not be called "Mother of God", but only that she should be called "Mother of Christ"), the layman, Eusebius, stood up and declared that we have an emperor but we have not a bishop!
Many people refused communion with Nestorius and, until Rome confirmed this declaration, he meted out severe punishments against those who rejected his authority; punishments that were given the full weight of the secular law (as there was no such concept of "separation of Church and State in those days).
The Church did not condemn those who remained in communion with Nestorius prior to Rome's confirmation that he had fallen from office, but the Church did praise Eusebius and others who rejected Nestorius's claim of the bishopric due to his fall from office for heresy. Furthermore, we should note that this was not even an issue about which the Church had formally declared at the time but one that could be logically reasoned if one knew the faith!
The problem of imposters who claim authority in the Catholic Church is tremendous and most of them have the "legal" claim to that authority according to the docuмents presented through Roman officials. But the fact is that most of those very people have not the Catholic Faith. How many traditional bishops are out there claiming jurisdiction? I don't know of any, though I don't doubt the possibility. But one must reject the so-called authority of the faithless, or should I say perfidious, bishops.
The case of the priestesses is much easier. Since women cannot be ordained (this is divine law) they cannot have authority even in the confessional. Many of these priestesses claim to have been ordained by a bishop "in good standing" with Rome. That may be so (they refuse to reveal his identity) but even he has lost the faith just as most of the clergy that reside, currently, in Rome. Unfortunately, one cannot simply rely upon "a website" to confirm or deny the authority of any particular bishop. One must know the faith!
The problem is at least a great as it was during the Arian Crisis of the early Fourth Century.