Twin (Earth-2042)

"Yoda spoke of another. The other he spoke of was your twin sister."

- Luke Skywalker and Obi-Wan Kenobi

Twins are two siblings born at the same time from the same parents. Luke Skywalker and Leia Organa were the twin children of Anakin Skywalker and Padmé Amidala

Technically speaking, a clone is also the twin of his or her template, since the two share the exact same genetic pattern. As such, Boba Fett was both the adopted son and the twin of Jango Fett.

Source

 * https://starwars.fandom.com/wiki/Twin