Can a woman perform I‘tikaf in her home?
No, a woman's I‘tikaf is not valid if performed at home, because her home is not a mosque.
What is the ruling of Islamic Law on the colored discharges that appear one or two days before the menstrual cycle?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
Colored discharges carry the same Islamic ruling as blood, whether they appear at the beginning or the end of the menstrual period. This remains true even if the discharge is intermittent—appearing for some days and stopping for others before returning—provided that the total duration does not exceed fifteen days nor fall short of a day and a night (24 hours). This is because the minimum duration of menstruation (Hayd) is one day and a night, while its maximum duration is fifteen days. Furthermore, the minimum period of purity (Tuhr) between two menstrual cycles is fifteen days, and there is no maximum limit for it. And Allah the Exalted knows best."
What is the ruling on performing dry ablution (tayammum) instead of the ritual bath due to severe cold?
Whoever is sick such that he cannot use water, or finds the water cold and heating it is not possible, and the person would be harmed by using cold water, it is permissible for him to perform tayammum. He must make up what he prayed with tayammum, because this is a place where there is water. And Allah the Almighty knows best.
What is the ruling on one who performs ablution or the ritual bath while having nail polish?
Nail polish must be removed before ablution or ritual bath so that water reaches what is beneath it, because it is a barrier that prevents water from reaching that area. This is based on the hadith narrated by Ali (may Allah be pleased with him) from the Prophet (peace be upon him): "Whoever leaves a hair's breadth of his body unwashed from major impurity, such and such will be done to him in the Fire." (Reported by al-Bukhari). And Allah the Almighty knows best.