Is it permissible for a woman to visit the doctor while in her `Iddah (waiting period)?
It is permissible for her to do that during day time, but it is impermissible for her to leave her house at night except for a sound reason. And Allah Knows Best.
Is it permissible for a woman to wear underwear while performing Umrah?
Yes, it is permissible for a woman to wear underwear while performing Umrah. This is because she should keep her regular clothes that cover all her body while being in a state of Ihram (ritual consecration) for Hajj, or Umrah. However, she should uncover her face and hands, but it is permissible for her to let her head-covering garment drape from her head down over her face when non-Mahram (i.e., marriageable) men pass by her. And Allah Knows Best.
Is it permissible for a woman who has become pure before the end of forty days of confinement to perform different acts of worship? and is it lawful for her husband to have sex with her?
Once postpartum bleeding ceases and she is certain that it won`t happen again, she becomes pure, and so she should perform Ghusl (ritual bath), pray, and fast. She can also have sex with her husband even before the end of (40) days because the minimum of postpartum bleeding is a moment, and the maximum is (60) days. However, the postpartum bleeding for the majority of women is (40) days, but this does not apply to rest of them.
What is the ruling of Sharia on a Muslim woman who committed Zina with a Christian and became pregnant as a result?
All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon Prophet Mohammad and upon all his family and companions.
Abortion is forbidden in Islam as it entails taking the life of a soul unjustly. Rather, it is one of the major sins; however, it is permissible only when there is well-established danger on the mother`s life; in which situation scholars gave priority to her life over that of the foetus, since this is, according to Sharia: "The lesser of two evils". In case a Muslim woman committed Zina (Adultery) with a Christian and got pregnant, if this did happen, then this question should be presented to the Iftaa` Committee with the presence of the questioner herself. She could also ask a reliable scholar face to face or via phone. If she gives birth to the baby, then he/she is a Muslim and takes the name of his mother; not the name of the man who was a reason for its conception. And Allah The Almighty Knows Best.