Thanks for your questions. The simplest answer re the canonical standing of the person in question is to ask her! That is always the first step. If this is somehow inadequate or is impossible, then the next step is to contact the local parish and see if they know the answer. Finally, you can call the chancery and ask them if there is a consecrated (c 603) hermit living on Vashon Island. If you know the person by name they will tell you whether she is a diocesan hermit and usually whether she is in good standing with the diocese, but they are not going to give you any further details regarding the person if they know her at all. If they ask if there are problems just let them know you merely want to verify the person's canonical standing unless (as you seem to imply) there is something more involved.

The conclusion and accusation that one is a "fake hermit" is a serious one. The charge ought not be leveled without real cause. While the term Catholic Hermit is authoritatively used by hermits with public vows and consecrations to indicate they live as hermits in the name of the Church, there are a handful of lay hermits (hermits in the lay state of life) who use the descriptor without having been authorized to do so. Some simply don't realize what they are doing is inappropriate. The person you are speaking of may well be a lay Catholic and hermit with or without private vows. The lay eremitical life, when lived authentically, is an entirely valid way to live eremitical life within the Church; it simply means the baptized person is living a private commitment in the lay state. She is not a religious (though she may be discerning admission to canon 603 with the diocese) and cannot claim to be living the eremitical life in the name of the Church. Still such a hermit lives her life as a Catholic lay person and represents a significant and living part of the eremitical tradition. Such a calling is to be esteemed.
Unfortunately, it cannot be denied that some individuals and some lay hermits do consciously and falsely try to pass themselves off as professed Religious or consecrated hermits. They either do know what they are doing is inappropriate and don't care, or they are wholly ignorant of the meaning of what they are doing I guess. Some do seem to believe one becomes a religious by making private vows --- which is simply not the case. Some seem to need a way to validate the failures in their own lives or desire a way to "belong" or have status they have not been granted otherwise (for genuine ecclesial standing is extended to the person and embraced freely by them; it is never merely taken). Some relative few use this as a way to beg for money or scam others. Others live isolated lives which are nominally Catholic, but without a Sacramental life or any rootedness in the local community. They validate this with the label 'hermit' but, whether lay persons or not, they are not living eremitical lives as understood and defined by the Church. Even so, let me reiterate, the conclusion of fraud is not one a person ought to leap to nor come to without serious cause.
By the way, one final possibility exists. You asked if Catholic hermits and canonical hermits are the same thing and the answer is yes. All Catholic hermits are canonical and live their vocation in the name of the Church. But some of these are solitary (c 603) and others belong to canonical communities (institutes). If the hermit you are speaking about belongs to a canonical community but is, for some valid reason, living on her own (say, on exclaustration while trying the eremitical vocation, for instance), then she will tell you what community she is professed with and be able to name her legitimate superior. (If she is lay person or former religious working with the Archdiocese to discern a vocation to canonical eremitism then she will tell you that too.) Again, while one should not pry, public vocations are just that and religious are answerable for these. Her identity, if she claims to be publicly professed, shouldn't be a secret, especially if she wishes to be known as a hermit. Similarly one shouldn't simply contact the chancery for any little thing without meaningful justification; however, if you have significant concerns for or about this person, then, presuming you have spoken to the person herself first to clarify matters, you can raise those with her legitimate superior or with Archbishop Sartain or the Vicar for Religious in the Archdiocese at the same time.
