Is the `Iddah (waiting period) of the divorced effective from the time the divorce took place, or from the time of registering it at the court?
It is considered effective from the very moment her divorce took place, but not from the time of registering it at the court. And Allah Knows Best.
Is permissible to buy/sell with non-Muslim?
Yes buying/selling for a Muslim with non-Muslim is permissible as regards what is lawful.
I am pregnant with four twins since two months although I didn't have childbearing potential during the last four years. In addition, the doctor specialized in reprusccusions, already has notified me about the possible reprusccusions as a result of being pregnant with four twins as follows: abortion, Metrorrhagia, Premature birth, high blood pressure, gestational diabetes and the like. What is the ruling on aborting some of the aforementioned embryos? A medical report was attached in which the status of my question is clarified.
All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Muhammad and upon all of his family and companions.
If the existence of the four embryos leads to critical reprusccusions/or threat on mother's health, life or a possibility of aborting all of them, then aborting one/two/three is permissible mitigate the above mentioned risks so long as the ages of the embryos don't exceed four months. And Allah Knows Best.
Is it permissible for a guardian (Big brother) to unlawfully stop his sister from getting married?
If the guardian denies her right in getting married for an unlawful reason, she should go to court in order to settle that matter, and the guardian is considered sinful in this case.