Yes, she was a sister, the middle sister, to be exact.

I have also discovered a half brother and two sisters.

I also found out that I had two half sisters and a half brother for siblings.

He has a younger sister, Morgan, and an older half-sister, Amanda.

You are my best friend, but sister would be a more appropriate term.

He immediately turned his attention to Francis’s 16-year-old half-sister, Constance Kent.

Suspicion for the crime fell upon Constance Kent, Francis's sixteen year old half sister.

In Randy’s case it is his mother, brother and sister; in Jimi’s case his half sister.

(4) The sister, including the half, and step-sisters.

your brother, sister, half brother, half sister, stepbrother, or stepsister, or their descendents

Yes, she was a sister, the middle sister, to be exact.

He was preceded in death by one brother; and one sister.

for the death of a brother or sister: one day; and

Brothers, sisters, half-brothers and half-sisters of the deceased;

Demi Lovato has discovered she has a secret half-sister.