How do you say I am looking for a roommate who is female in spanish?

There are several ways to say "I am looking for a female roommate" in Spanish, depending on the level of formality and the nuance you want to convey:

* Busco una compañera de piso mujer: This is a straightforward and common translation. "Compañera de piso" means roommate, and "mujer" specifies female.

* Busco una compañera de piso que sea mujer: This is a slightly more formal and explicit way of saying it. "Que sea mujer" adds emphasis on the female requirement.

* Busco una chica para compartir piso: This is a more informal option. "Chica" means girl, and implies a younger female roommate. "Compartir piso" means to share an apartment.

* Necesito una compañera de piso (mujer): This translates to "I need a female roommate," using parentheses to clarify the gender.

The best option depends on the context. For a formal advertisement, the first two options are preferable. For a more casual conversation, the third option might be suitable. The last option is a good compromise between clarity and formality.