This is the 4301st most frequent Swedish word.
storasyster
Older sister.
Here, 'storasyster' refers to the speaker's older sibling and is used in a possessive form.
Min storasyster är väldigt snäll.
My big sister is very kind.
In this sentence, 'storasyster' is used to refer to someone else's older sibling.
Jag såg att din storasyster hade en ny bok.
I saw that your big sister had a new book.
In this case, 'storasyster' is used as a general or familial term without explicit possession.