Fatwa no.
7105
I did not consummate the marriage with my wife. Is it permissible for me to marry her daughter from her second husband?
A:
If the reality is that you did not consummate the marriage by having intercourse with that woman, it is permissible for you to marry her daughter. Allah (Exalted be He) says:
...your step daughters under your guardianship, born of your wives to whom you have gone in - but there is no sin on you if you have not gone in them (to marry their daughters)
(Part No. 18; Page No. 212) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.