Forceful marriage with maternal uncle, need divorce

Asking this question on behalf of a friend One of my friend’s families got her married to her own maternal uncle, knowingly or unknowingly. It is a matter of 2013. Those people are Muslims. Those days the conditions of her house were not good. Her father was ill and it was difficult to manage the expenses of the house, then the maternal uncle used to help with a little money. Her maternal uncle looks mental because it is because of this that her dirty eyes fell on her niece and he married with her niece. Don’t know what their family thought and how did they agree to marry with maternal uncle which is not permissiable. Moreover, even the villagers did not stop nor did the maulvi who did the nikah. The girl used to stay at maternal uncle’s house due to studies and all this happened at that time. Well, the girl was not agree with this marriage and her maternal uncle used to keep harassing her. When her studies were completed, she left her maternal uncle’s home and came to her house in 2016. They are not living together since then. Later she comes to the city and is working as a software engineer in an MNC company. That girl now wants to settle her house by marrying another, but her maternal uncle is not divorcing her. What does Indian law say about this? What is the solution?