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 go out at night except for a sound reason.
Is it permissible for one to give the Zakah(obligatory charity) to his indebted brother?
It is permissible for one to give the Zakah to his indebted , or poor brother.
Is it permissible for the woman who is observing Iddah after her husband`s death to sit with her daughter`s suitor, although their marriage contract hasn`t been concluded yet?
All perfect praise be to Allah the Lord of The Worlds. May His blessings and peace be upon our Prophet Mohammad and upon all his family and companions.
A suitor who hasn`t concluded the marriage contract isn`t a Mahram*, so he must be treated as such. And Allah The Almighty Knows Best.
* The period a woman must observe after the death of her husband or after a divorce, during which she may not marry another man.
* In Islam, a mahram is a member of one's family with whom marriage would be considered haram, concealment purdah, or concealment of the body with hijab, is not obligatory; and with whom, if he is an adult male, she may be escorted during a journey, although an escort may not be obligatory.
Is Aqeeqah due on the miscarried embryo?
No Aqeeqah is due on the dead embryo.