No. A woman's sister's husband is not Mahram of the woman. Mahram is a person who cant marry that woman in any circumstances. A woman's husband may divorce his wife and marry her sister. Therefore, he is not he rMahram. Father, father's father, real brother and his off-spring, real ucle, husband's father, real nephew, step brother, step son, are a few Mahrams of a woman who are forbidden to marry her. She may perform Hajj with them.
This is a debated topic. Some say a woman must have a mahram, others say it is not necessary if she will be safe.
If a wife wishes to accompany her husband on the pilgramage (Hajj) she is entitled to. Most Islamic schools of jurispudence require a woman to be accompanied by a "Mahram" which is a male being her husband or another mail whom she cannot legally marry such as her brother, father, uncle, etc. However, in recent times it is becoming increasingly acceptable for woman in groups to perform the pilgramage without any Mahram or just one Mahram as a sort of "guardian".
The Muslims perform Hajj because it is obligatory on each Muslim man and woman to perform Hajj once in lifetime provided he/she can afford.
A Muslim woman cannot perform Hajj (pilgrimage to Mecca) without one of her blood-relatives.
No true Muslim should disagree in this regards. No Muslim woman is permitted by the Prophet (SAW) to travel without a male member of her real relationship- Mahram. A mahram is a relative (father, son, brother, husband, nephew) with whom in no case her marriage is permitted.
In case there is no danger of miscarriage or something else, pregnant woman may perform Hajj. It takes only a few days to perform Hajj.
Sure, by all means. Hajj is the fifth pillar of Islam. Performing Hajj once in lifetime is obligatory on each Muslim man and woman if he/she can afford.
Ofcourse a person can perform Hajj for 2nd time.
The Muslims perform Hajj. It is obligatory on them once in lifetime.
All Muslims must perform Hajj at least once in a lifetime.
Hajj is obligatory on a Muslim man and woman once in life time.
The Muslims from all over the world come to Mecca to perform Hajj.
No, the Muslims are not required to perform Hajj annually. It is obligatory once in life under certain conditions. Anyhow, if a Muslim can perform Hajj every year, it is not prohibited.