A female foundling is not entitled to inheritance

Q: My father (may Allah be merciful to him) adopted a baby girl, whom he found hung on a tree after her birth. My mother breast-fed her along with me, as I was also then a newborn. Then she grew up and got married. Later on, my father died (may Allah be merciful to him). Now she has grown children who demand a share in the estate of my father. Please give me your Fatwa regarding whether she has a right to my father's estate or not. Whatever the ruling, I hope that your Fatwa will be in writing in order to convince her and her sons, as your Fatwa would be decisive for both parties.It is worth mentioning that we have not deprived her as we gave her two-thirds of the share each legal heir of my sisters would receive.

A: If the case is as you mentioned, this lady deserves no share of the estate (Part No. 16; Page No. 514) your father left, for she is not one of the heirs. Your father's taking care of her and keeping her in his custody until she grew up and got married is a gesture of kindness on his part. May Allah grant us success. May peace and blessings be upon our Prophet, his family and Companions.