Andrew Hunter's grandmother

The next generation up in the fake Guise pedigree claims that Edwyna inherited the titles from her mother, "Princess Marie-Jeanne", who is said to have died in 1962.

In fact, Andrew Hunter's maternal grandmother, as we have seen from Edwyna's birth certificate, was the rather more prosaically named Maria Jane Cossey nee Roussell, born in New Zealand in 1882.  Her father was a labourer who had emigrated from France via Jersey.  For what it is worth, Maria Jane had brothers whose descendants are still living, so even if the family did have a title, it would have passed to them rather than to her.  Clearly she didn't let facts or logic get in the way of a good story, a trait which seems to have been handed down in her line.

Maria Jane ran dairy cattle on a farm near Auckland.  At some point, she and her husband abandoned the surname Cossey altogether, and ended up using the name 'de Guise-Roussel'.

Here are her birth, death and marriage certificates:

Given that Maria Jane had brothers, whose male-line issue remains extant in New Zealand today, how is that she succeeded to the family "titles"?  No other princely titles are known to descend in such a haphazard and illogical fashion.