inheritor vs inheritrix

inheritor and inheritrix both are nouns.

Word	Noun	Adjective	Verb	Adverb
inheritor	Yes	No	No	No
inheritrix	Yes	No	No	No

As nouns, inheritrix is a hyponym of inheritor; that is, inheritrix is a word with a more specific, narrower meaning than inheritor:

inheritor: a person who is entitled by law or by the terms of a will to inherit the estate of another
inheritrix: a female heir

Other hyponyms of inheritor include heir apparent, heir-at-law, heiress, inheritress, heir presumptive.

inheritor (noun)	inheritrix (noun)
a person who is entitled by law or by the terms of a will to inherit the estate of another	a female heir