What is Femme?

Legal Definition
Femme is a term that can be used by nonbinary people's identity as it relates to femininity or used by women, female-identifying people, and trans-women. Femme as a gender identity usually denotes that an individual who is, "non-binary or queer femme gender specifically and inherently addresses femmephobia and the systematic devaluation of femininity as part of their politics". The term is used exclusively for queer people regardless of whether they identify as female. This title can apply within any gender identity or sexual orientation, such as trans-men or women, genderqueer people, and cis-gendered people. Thus, contrary to popular belief, the title femme doesn't reinforce the gender binary but can work within and without it. A Femme identified person doesn't always have to be dressing or acting "traditionally feminine" (meaning a feminine aesthetic such as wearing makeup, heels, and numerous accessories) but also has to do with behaviors, interactions, political views, etc. Although it originated from the dichotomous relationship between butch and femme, femme is an "independent, autonomous gender expression" which doesn't need masculinity to help define it or attract them sexually, since relationships between two people who identify as femmes is possible.
-- Wikipedia
Legal Definition
Woman.

2. This word is frequently used in law. Baron and feme, husband and wife; feme covert, a. married woman; feme sole, a single woman.

3. A feme covert, is a married woman. A feme covert may sue and be sued at law, and will be treated as a feme sole, when the husband is civiliter mortuus. Bac. Ab. Baron and Feme, M; see article, Parties to Actions, part 1, section l, §7, n. 3; or where, as it has been decided in England, he is an alien and has left the country, or has never been in it. 2 Esp. R. 554; 1 B. & P. 357. And courts of equity will treat a married woman as a, feme sole, so as to enable her to sue or be sued, whenever her husband has abjured the realm, been transported for felony, or is civilly dead. And when she has a separate property, she may sue her husband in respect of such property, with the assist ance of a next friend of her own selection. Story, Eq. Pl. §61; Story, Eq . Jur. §1368; and see article, Parties to a suit in equity, 1, n. 2; Bouv. Inst. Index, h. t.

4. Coverture subjects a woman to some duties and disabilities, and gives her some rights and immunities, to which she would not be entitled as a feme sole. These are considered under the articles, Marriage, (q. v.) and Wife. (q. v.)

5. A feme sole trader, is a married woman who trades and deals on her own account, independently of her husband. By the custom of London, a feme covert, being a sole trader, may sue and be sued in the city courts, as a feme sole, with reference to her transactions in London. Bac. Ab. Baron and Feme, M. 6. In Pennsylvania, where any mariners or others go abroad, leaving their wives at shop-keeping, or to work for their livelihood at any other trade, all such wives are declared to be feme sole traders, with ability to sue and be sued, without naming the husbands. Act of February 22, 1718. See Poth. De la Puissance du Mari, n. 20.

7. By a more recent act, April 11, 1848, of the same state, it is provided, that in all cases where debts may be contracted for necessaries for the support and maintenance of the family of any married woman, it shall be lawful for the creditor, in such case, to institute suit against the husband and wife for the price of such necessaries, and after obtaining a judgment, have an execution against the husband alone and if no property of the said husband be found, the officer executing the said writ shall so return, and thereupon an alias execution may be issued, which may be levied upon and satisfied out of the separate property of the wife, secured to her under the provisions of the first section of this act. Provided, That judgment shall not be rendered against the wife, in such joint action, unless it shall have be proved that the debt sued for in such action, was contracted by the wife, or incurred for articles necessary for the support of the family of the said husband and wife.
-- Bouviers Law Dictionary