ANSWER:

If her mother breastfed you more than 5 times when you were under 2 years of age then you’re her mahram and you cannot marry her. 

But if this is not the case then no problem in marrying her. 

Can I do Nikkah with my cszn. she is my milk sister also.Her mother has given me milk on some occassions…..Is he Mahram or Non Mahram for myself….is this Nikkah valid or not?

Fiqh of Marriage, Mahram |