ANSWER: The father in law is the permanent mahram.  Even if his son divorces the woman or if the son dies then also the father in law is a permanent mahram for life for this woman.

Read more

ANSWER: No, you must not make up that rakah.  You are exempted from reciting fateha and this rakah is valid if you caught the imam in ruku and you got to say the prescribed dhikr at least once. 

Read more