Is it permissible to marry a girl whose older brother was suckled with my brother, and whose younger sister was suckled with my sister, without any suckling between her and me?

If you and the girl did not suckle from the same woman, then she is not among your unmarriageable kin (mahram), and the suckling of her older brother with your brother, or the suckling of her sister with your sister, does not make her unlawful for you. What is considered are five satisfying sucklings.