Mag-asawa sila.
They're husband and wife.
They're a married couple.

Magkapatid sila.
They are siblings.
= They are brothers.
= They are sisters.
= They are brother and sister.

Mga kamag-anak mo ba sila?
Are they your relatives?

Mga pinsan ko sila.
They are my cousins.

Sino ang panganay?
Who is the oldest [sibling]?

Ako ang bunso.
I am the youngest [sibling].

Ay, ang apo ko!
Oh, my grandchild!