You should assume that you have performed 3 units (rakat) and finish the prayer after performing one more rakat. After you finish the prayer (saying salam), without turning to the sides (meaning you are still in prayer) you should pray one rakat Ihtiyat-prayer (standing) as an obligatory precaution. It is a one unit prayer which symbolize the third or forth rakat. 

A brother that has studied the Book of Enoch says that the Ahl al-Bayt (AS) are mentioned in the seventh phase. If you would like his contact, I can provide it iA.

I have checked through the whole translated text of the Book of Enoch, and cannot see the quote you mention anywhere.

Here is a link to the pdf. It does not mention the names that have been cited in the title that you have mentioned.

https://www.holybooks.com/wp-content/uploads/The-book-of-Enoch.pdf

No it is not a sin to say this to the husband.

It is a sin to deny him his conjugal rights, but you may use a method of contraception.

The Qur'an and hadith indicate that there was an instantaneous revelation in a compressed form to the heart of the Prophet (S), and then a gradual revelation in the course of the 23-year mission of the Prophet (S)

It is not shirk for human beings to ask one other for help. What is shirk is to consider them to be able to help independent of God's will.

Regards

Abbas