also: そうし
She gave birth to twins.
I have an older twin brother.
Even though they are twins, their personalities are completely different.
She gave birth to twins last month.
He is my twin brother.
They are identical twins and look very much alike.
Practical kana spelling, often used when a softer or easier-to-read style is preferred.
Attested kanji spelling, uncommon for the ordinary word 'twins'.
Attested mixed kana-kanji spelling, but much less common than 双子.