What is the ruling of Islamic law on not paying Zakat throughout one's life? Is Zakat obligatory for someone who relied on her father and husband for financial support? And how can one compensate for the Zakat that was missed?

Zakat becomes obligatory on wealth if it reaches the nisab and a full hawl (lunar year) passes over it. Therefore, whoever does not possess wealth, or possesses wealth below the nisab, is not obligated to pay Zakat. The nisab is equivalent to 85 grams of gold or 595 grams of silver. If you possess the nisab and a full year has passed over it, then you must pay Zakat for the past years, provided that your father or husband did not pay its Zakat with your permission.