Is the mother's husband and the divorced father's wife among the mahram (relatives one may not marry)?
Machine translationRead the Arabic original
The questioner : This questioner, the mother of Faisal, asks: Is the mother’s husband considered a mahram (a relative one may not marry) to the daughter?
The Shaykh : She means the daughter from another husband; otherwise, from him, she is his daughter.
The questioner : Is the divorced father's wife permissible for the father's son to shake hands with, and is she a mahram?
The Shaykh : The answer is yes. The divorced father's wife is a mahram for his son, even if the father divorced her.
The Shaykh : She means the daughter from another husband; otherwise, from him, she is his daughter.
The questioner : Is the divorced father's wife permissible for the father's son to shake hands with, and is she a mahram?
The Shaykh : The answer is yes. The divorced father's wife is a mahram for his son, even if the father divorced her.
Source
الفتاوى الثلاثية (1) - 1 — binothaimeen.net (55:57)
The Arabic text is a machine transcription of the audio recording.