Can a man who fornicated with a woman still marry her daughter?
Scholars differ in regards to if a man can marry the daughter of a woman he fornicated with. The Shaafi'i school is of the opinion that he can marry the daughter of a woman he fornicated with. This is also one opinion in the Maaliki school of thought.
Imaam al-Shaafi'i said:
وإذا زنى الرجل بامرأة فلا تحرم عليه هي إن أراد أن ينكحها، ولا أمها ولا ابنتها
If a man fornicates with a woman, she is not made impermissible for him if he intends to marry her, neither her mother nor her daughter.
The Maaliki say: Indeed, the haraam does not make the halaal haram.
According to the Hanafi and Hanbali schools of thought if a man fornicates with a woman, he cannot marry her daughter. This is also an opinion in the Maaliki school of thought.
Ibn Qudaamah says in al-Mughni on Page 117 Volume 7:
When a man fornicates with a woman she becomes impermissible [to marry] for his father and son, and her mother and daughter become impermissible for him [to marry].