It is permissible for your brothers to marry your sisters through breastfeeding

Question: I am a young man who was breastfed by my maternal uncle’s eldest daughter. Other sisters were born after her, and she is now married. Is it permissible for me or any of my brothers to propose to one of her sisters?

Answer: If your breastfeeding, O questioner, was from your maternal uncle’s wife, and it was five breastfeedings or more while you were within the two-year period, then all your maternal uncle’s daughters are your sisters, and you are not permitted to marry any of them. As for your brothers who were not breastfed by your maternal uncle’s wife, there is no blame on them if they marry your maternal uncle’s daughters, provided that your maternal uncle’s daughters were not breastfed by your brothers’ mother, nor by your father’s wife, nor by your sisters.
In summary: there is no blame on your brothers if they marry their maternal aunt’s daughters, provided that there is no breastfeeding between them that would prohibit it. As for your breastfeeding, O questioner, from your maternal uncle’s wife, it is specific to you and does not make your maternal uncle’s daughters forbidden to your brothers.
And success is from Allah.