Paying Zakat on gold jewelry given as a wedding gift 6 years ago

One of my students asked me the following question: Whether she has to pay Zakaat for the gold she received six years ago as a Mahr (wedding-gift). At first she was told that the gold is just to make herself pretty for her husband and women in her family. Result is that she did not pay Zakaat over the gold for these six years. Does she have to pay or not? And if yes, does she have to pay for all the six years she has had the gold?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

The majority of scholars are of the view that there is no Zakat on jewellery that is used as an adornment, this is explained in Fataawa: 82925 and 83576. So whoever believes that the opinion of the majority of scholars is correct which waives Zakat on jewellery that is used as an adornment and then later changes his conviction to believe that the preponderant opinion is that Zakat has to be paid on adornments, according to the opinion of the Hanafi school, then he is not obliged to pay the Zakat on the previous years. Because a Muslim is not obliged to make up for what he had missed if his actions were based on a Fatwa of a trustworthy Imaam or scholar. He just has to pay the Zakat from the time he acts according to the school of Abu Haneefah. However, if he had not paid Zakat for the previous period because he was negligent despite him/her believing that it is an obligation, then in such a case he has to pay the Zakat for the previous years.

Allaah knows best.