sa collection

his/her collection

→ son
phrase Rare #39,363
his/her collection Sa agrees with the feminine noun collection, not the owner's gender; it can mean “his,” “her,” or “its” collection.
FR: Elle a rangé sa collection dans une vitrine.
EN: She put her collection in a display case.

Tom montra sa collection de timbres à Mary.

Tom showed his stamp collection to Mary.

Tu serais le joyau de sa collection.

You would be the jewel in his collection.

— Harry Potter et le Prince de sang-mêlé (2009)

Tom est fier de sa collection de timbres.

Tom is proud of his stamp collection.

Il m'a montré sa collection de timbres-poste.

He showed me his stamp collection.

Samy a montré sa collection de billes à Layla.

Samy showed his marble collection to Layla.

Chaque matin le tsar passait sa collection en revue.

Every morning the tsar reviewed his collection.

— L'Arche russe (2002)

C'est officiel, voici le titre le moins disco de sa collection.

It’s official: this is the least disco title in their collection.

— Seul sur Mars (2015)

Mon frère prend grand plaisir à sa collection de timbres.

My brother takes great pleasure in his stamp collection.