التَّغْلِيبُ
Using the form or name of one member of a pair or group for both or for the group as a whole.
وَكَانَتْ مِنَ الْقَانِتِينَ
And she was among the devoutly obedient. (Al-Tahrim 66:12)
Mary is referred to in a sentence containing the masculine sound plural “القانتين”, which follows the established usage of masculine predominance for a mixed class. It does not change the gender of the referent.
Taghlib extends a conventional linguistic form over an included category.