What does “female” mean for the Female Changeling?

Question

This question Why do the other changelings look like Dr Mora? deals with why the changelings take on the appearance they do. But why is the Female Changeling female?

Is there a biological basis for gender in the Changelings? Shouldn't they be genderless? Is this a choice she made for dealing with Solids?Do Shapeshifters, like Odo, shift just shape, or composition as well? talks about how the changelings don't have parts.

Note: Before anyone says it and implies I'm somehow shortsighted to assume male is the default, I do realize you could ask why the other Changelings are male. You could ask this question about any number of aliens encountered in Star Trek. That's another question. The changelings are unique however, since it's not obvious whether/why they have gender and also because they choose their appearance. Presumably if the Changelings really are genderless, then the answer for Odo is due to Dr. Mora. At any rate, the female changeling is special because she is unique and is actually known as The Female Changeling.

Answer 1

When script writers don't assign a name to a character, they often simply use a description: GUARD #1, KLINGON #3, etc. Often, these descriptions make it all the way to the credits, because there's no better way to describe the character.

In this case, I expect it was something similar: having cast Salome Jens to play the spokesperson for the Changelings in "The Search", and having not given her a name, she was described in the script as FEMALE CHANGELING. When Jens became a recurring guest playing, for all intents and purposes, the same character, who eventually said explicitly that Changelings don't have names, the descriptor stuck.

Everything we know about changelings (mostly from the "Female" Changeling's lips) is that they have no actual gender in their natural, liquid form. She is occasionally referred to as "female" (specifically in "Favor the Bold"), and characters do regularly use "she/her" as a pronoun for her. However, that could be seen as solids using their conventions for lack of anything better. Certainly, a Vorta is not about to refer to one of his gods as "it", and use of "they" as a first-person-neutral is grammatically controversial.

From an in-universe perspective, we could say that the character adopted a conventional humanoid-solid appearance for convenience's sake, chose a female one for no better reason than contrast, or perhaps even whim, and then maintained it later because it made her recognizable to the solids she needed to interact with.

But in the end, the main reasons are out-of-universe: Salome Jens was cast once, nailed the part, and thus returned to play it repeatedly thereafter. Jens is female, and they chose not to disguise this fact, and thus: FEMALE CHANGELING.

Answer 2

I suppose that the female changling is called the female changeling in the credits because she was made up to look sort of like what they imagined a female changling, if there was one, would look like.

And the make up and costume people probably made the female changling look sort of female because the character was portrayed by a female actor and they would have felt uncomfortable making her look masculine.

Also once the arc where Odo sort of romanced the female changling would seem a little odd to most viewers if the female changeling was depicted ore like a male changeling.