Informally, it would be "tu hermanastra." In a formal context, or when speaking to a stranger or someone older than you, etc., it would be "su hermanastra."
My stepsister.
"Stepbrother" in Spanish is "hermanastro". It is pronounced "air-mah-NAHS-tro". Please see this site for confirmation of the translation: http://www.answers.com/library/Translations
The possessive form of the singular noun stepsister is stepsister's.Example: I'm making a cake for my stepsister's birthday.The plural form of the noun stepsister is stepsisters.The plural possessive form is stepsisters'.Example: The wicked stepsister's taunts made Cinderella sad.
stepmother, stepsister and the other stepsister
The word for "stepsister" in Welsh is "chwegrwn."
Oprah Winfrey's stepsister's name is Patricia.
Gregory Maguire wrote Confessions of an Ugly Stepsister.
The duration of Stepsister from Planet Weird is 1.42 hours.
Confessions of an Ugly Stepsister has 368 pages.
yes
There is no history of Bow Wow having a stepsister :)
The singular possessive form is stepsister's.Examples: This is a gift for my stepsister's birthday.