Who are the sisters through breastfeeding?

Your foster sister is the one who was suckled with you by the same woman five times or more during the first two years of life. So, if your female cousin was suckled by your mother five times within the first two years, she is your foster sister, and your mother is her mother. And if you were suckled by your paternal aunt five times within the first two years, then your paternal aunt's daughters are your foster sisters, and your paternal aunt is your mother, and her husband is your father through fosterage, and his daughters from other women are also your sisters.