Maria was a king and Hatshepsut was both a pharaoh and a king. This is such surface level knowledge about them that even their wikipedia articles mention it, I literally just checked to make sure I didn't fuck up my historical figures since you made me second guess myself.
You might be mistaking Maria of Anjou (Mary I) for Marie of Anjou due to their similar names.
Might've been, first thing that came up was queen of somewhere. Reading up on Hatshepsut was especially interesting, gender roles were comparatively pretty important during her reign to point where her portraits showed her as having a man's body with a beard(a spiritual image she was trying to present to her subjects as I understood it). Maria was comparatively a less interesting case, being crowned król or king as it is translated to represent she was a ruler in her own right.
The reasons for both still indicate to me in context a claiming of male authority for themselves, and we don't live in that world anymore. Culture has changed alot since queen or "cwen" simply meant wife. Just like faggot used to mean a stick(which can lead to some confusion when reading some older robinhood books I've personally discovered), or gay used to mean cheerful/happy, or humour as a reference to blood. Even as early as the 17th century when the English were translating their holy book(an extremely tedious and precise process involving atleast 60 different people including translators, revisers, editors and overseers) the ruler of southwestern arabia was referred to as queen. People who spoke english in that time knew it wasn't just some guy's wife, but the ruler of a country.
Today it's even more so the case, english dictionaries describe king as a male ruler and queen as a female ruler. Non-english speaking nations that may claim female kings don't actually use the word king, it's a translation to english from whatever word they actually use intended to convey a certain meaning. Namely to rule as a masculine figure, specifically in cultures where gender roles are notably divided.
Your insights are fascinating and I enjoyed the rabbit hole they sent me down, however it still seems to me that the title in question, calling her a "demon king" just lends to more confusion and imprecision than necessary. it's not being translated to egyptian or polish, it's being translated to english, that is, modern english. On the otherhand, english is a living language and I can look up words today that have different dictionary definitions from even five years ago, so maybe the english word for king will change if this sort of thing is done enough.