If she breastfed you five times or more when you were within two years
of age or less, she is you r mother and all her children are your
siblings and their daughters are your nieces and such a marriage is
void and invalid as you are her mahram.

I was breastfed by a lady in her late 40s. Her milk was not white and it came without pregnancy and i drink it although it was yellow milk. Now i married to her granddaughter. Is my marriage valid.? Although i considered that lady as my mother in her life but things juat happen this way.