I did not consummate the marriage with my wife. Is it permissible for me to marry her daughter from her second husband?
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.