A persons's muliebrity is her femininity or womanliness. An idolizing kindergartner might admire her dress-wearing, curly-haired teacher's muliebrity.
The noun muliebrity is quite uncommon, and today it's almost always used in a literary context. A poet might describe a beautiful woman's muliebrity, for example. The word comes from the Late Latin word muliebritas, "state of womanhood," which is rooted in one of the Latin words for "woman," mulier.